Revisions in Nepenthes following explorations of the Kemul Massif and the surrounding region in north-central Kalimantan, Borneo

Abstract

An expedition to the highest peak of the Kemul Massif located a number of different Nepenthes taxa, including the type populations of N. fusca and N. mollis, neither of which have been observed in situ since they were first collected in 1925. Studies of the type form of N. fusca show that two further species should be considered, one largely restricted to Sabah’s Crocker range—here reinstated as N. zakriana—the second a southerly distributed species from Brunei, Sarawak and Kalimantan, named here as N. dactylifera. Analysis of the type population of N. mollis indicates that N. hurrelliana is a heterotypic synonym of N. mollis, and reveals an additional undescribed Nepenthes species from Sarawak and Kalimantan with a widespread but highly localised range.

Full text

Phytotaxa 392 (2): 097–126
https://www.mapress.com/j/pt/
Copyright © 2019 Magnolia Press Article PHYTOTAXA
ISSN 1179-3155 (print edition)
ISSN 1179-3163 (online edition)
Accepted by Duilio Iamonico: 17 Jan. 2019; published: 14 Feb. 2019
https://doi.org/10.11646/phytotaxa.392.2.1
97
Revisions in Nepenthes following explorations of the Kemul Massif and the surrounding
region in north-central Kalimantan, Borneo
ALASTAIR S. ROBINSON1*, MICHAL R. GOLOS2*, MARC BARER3, YOSUKE SANO4, JENNIFER J. FORGIE5,
DIEGO GARRIDO6, CHANDLER N. GORMAN7, ADI O. LUICK8, NICK W. R. MCINTOSH9, STEWART R.
MCPHERSON10, GREGORY J. PALENA11, IVAN PANČO12, BRIAN D. QUINN13 & JEFF SHEA14
1 National Herbarium of Victoria, Royal Botanic Gardens, Melbourne, VIC 3004, Australia; email: alastair.robinson@rbg.vic.gov.au
2 School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK; email: michal.golos@bristol.ac.uk
3 18–34 Waverley Street, Bondi Junction, NSW 2022, Australia.
4 Graduate School of Human Sciences, Waseda University, 359–1192 Saitama, Japan.
5 Lower Tropical Nursery, Royal Botanic Gardens Kew, Richmond, Surrey, TW9 3AE, UK.
6 508 Clinton Drive, Gastonia, NC 28054, USA.
7 University of California Davis, 1 Shields Ave, Davis, CA 95616, USA.
8 Obergraben 15, 01097 Dresden, Germany.
9 69 Lansdowne Crescent, West Hobart, TAS 7000, Australia.
10 Redfern Natural History Productions, 61 Lake Drive, Hamworthy, Poole, Dorset, BH15 4LR, UK.
11 116 West Maple Ave 2B, Denver, CO 80223, USA.
12 Wimbledon Park Golf Club, Home Park Road, London, SW19 7HR, UK.
13 231 Morrin Road, St Johns, Auckland 1074, New Zealand.
14 2785 Goodrick Avenue, Richmond, CA 94801, USA.
* Authors for correspondence
Abstract
An expedition to the highest peak of the Kemul Massif located a number of different Nepenthes taxa, including the type
populations of N. fusca and N. mollis, neither of which have been observed in situ since they were first collected in 1925.
Studies of the type form of N. fusca show that two further species should be considered, one largely restricted to Sabah’s
Crocker range—here reinstated as N. zakriana—the second a southerly distributed species from Brunei, Sarawak and Kali-
mantan, named here as N. dactylifera. Analysis of the type population of N. mollis indicates that N. hurrelliana is a hetero-
typic synonym of N. mollis, and reveals an additional undescribed Nepenthes species from Sarawak and Kalimantan with a
widespread but highly localised range.
Keywords: Indonesia, Malesia, Nepenthaceae, new species, non-core Caryophyllales, taxonomy
Introduction
Nepenthes Linnaeus (1753: 955) (Nepenthaceae Dumort.) comprises at least 160 species and is one of the world’s
largest carnivorous plant genera (Clarke et al. 2018). Nepenthes is widespread within the Malesian phytogeographic
region, with centres of diversity in Borneo, the Philippines, and Sumatra (Robinson et al. 2009, Cheek & Jebb 2001,
Clarke 2001a), although the majority of species are known from individual mountains or just a few closely-situated
mountain tops. This endemism is thought to be the result of allopatric speciation caused by vicariance within the
principal territories occupied by Nepenthes (Robinson et al. 2009).
Danser (1928) in his “The Nepenthaceae of the Netherlands Indies” recognised just 65 Nepenthes species
worldwide, including 17 new species. Among the latter were N. fusca Danser (1928: 288) and N. mollis Danser (1928:
338), both described from material collected by Frederik Endert from the flanks of the Kemul Massif (1500 m a.s.l.
for N. fusca, 1800 m a.s.l. for N. mollis). Endert was the lead botanist and plant collector on the 1925 Midden-Oost-
Borneo Expeditie (Central East Borneo Expedition) that ran from April to December of that year (Indisch Comité voor
Wetenschappelijke Onderzoekingen 1925, Indisch Comité voor Wetenschappelijke Onderzoekingen ca. 1926, Buijs
et al. 1927, Endert 1927). Since Endert’s time, no botanical expeditions have been made to the Kemul Massif and this
fact has led to taxonomic questions for both N. fusca and N. mollis.

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Although Danser’s description of Nepenthes fusca is largely complete, a detailed description of lid characters is
lacking, particularly for the upper pitcher lids which are absent from two of the four type accessions (lectotype and
isotype at BO), an issue compounded by possible artefactual folding of the pressed lids in the remaining accessions
(isotypes at K and L). Since lid morphology is regarded as a crucial diagnostic characteristic (see e.g., Clarke et al.
2018) of a number of Nepenthes sections, interpretations of what constitutes N. fusca have varied. For example, plants
with very narrowly triangular lids from Sabah’s Crocker Range, including Mt. Kinabalu, were assigned to N. fusca
by Kurata (1976), an interpretation that quickly gained wide acceptance (Clarke 2006). It is this Sabah taxon that has
been most commonly referred to and illustrated as N. fusca, the narrow lids of the upper pitchers being the principal
diagnostic characteristic. A closely related taxon is also found across the central highlands of Sarawak, at least as far
north as Gunung Mulu National Park, as well as in Brunei and Kalimantan. Substantive morphological differences
between the Sabah and Sarawak taxa have long been appreciated, and the two were initially treated separately. Phillipps
& Lamb (1988), who were the first to illustrate the Sarawak plant, treated it as an undescribed species, as did Clarke
(1997) in his monograph on Bornean Nepenthes. Jebb & Cheek (1997) introduced a broad circumscription of N. fusca
that, in addition to the Kemul and Sabah plants, also encompassed the taxon from Sarawak. This interpretation was
accepted and followed in most subsequent works (Cheek & Jebb 2001, Clarke 2001b, Clarke & Lee 2004, Phillipps et
al. 2008, McPherson 2009, McPherson & Robinson 2012).
Although discrepancies between the Nepenthes fusca type description and the taxa from Sabah and Sarawak
were noted by the various authors, a definitive resolution of how to correctly circumscribe N. fusca could not be made
without living reference material from the type locality bearing intact lids. Interestingly, the figure accompanying
Danser’s (1928) description of N. fusca shows upper pitchers with ovate, complanate lids—markedly different from
the extremely narrow and revolute lids of the plants from Sabah and Sarawak—the description itself simply stating
that the lids of the upper pitchers are “like those of the lower pitchers”, viz. narrowly ovate and sub-cordate, with an
applanate appendage towards the base. The abbreviated description led Jebb & Cheek (1997) to suggest a possible
explanation for the discrepancy: that the lids of the upper pitchers in the plate were drawn not from real specimens
but copied from preserved lower pitchers. However, they later note in Cheek & Jebb (2001) that “the isotypes at K
and L have upper pitchers with the characteristic lid”, which one must assume refers to those with revolute margins.
Examination of the isotype at K (Endert 3955) does reveal a lid with folded margins, but the single fold (rather than
rolled edges) of the margin does little to rule out suspicions that the material was inaccurately pressed.
Only Adam
et al. (1992) deviated from the aforementioned broad consensus by maintaining a narrow circumscription
of Nepenthes fusca. Adam and his colleagues considered the Sabah plants to represent N. curtisii Masters (1887: 681)
(Adam 1998, Adam & Wilcock 1998), a problematic taxon based on cultivated material of uncertain provenance, and
which is now generally regarded as a synonym of N. maxima Reinwardt ex Nees von Esenbeck (1824: 369) (Cheek &
Jebb 2001). They initially described it as Nepenthes curtisii subsp. zakriana Adam & Wilcock (1998: 151), but later
elevated it to species rank as Nepenthes zakriana (Adam & Wilcock) Adam & Hamid (2006: 434). This taxon was
considered by other authors to fall within the wider interpretation of N. fusca s.lat., and was treated as such by Phillipps
et al. (2008) and McPherson (2009).
Concerning Nepenthes mollis, the type material (at BO) consists of one stem fragment without pitchers. As Danser
(1928) reported, although “the pitchers are unknown, the other parts are so peculiar and differ from all other species in
such a striking manner, that it seems allowed to me to base a new species on it.” N. mollis is the only Nepenthes besides
N. ephippiata Danser (1928: 286) and N. villosa Hooker (1852: tab. 888) to be described with unknown pitchers
(though Danser was able to include pitcher material of the former in a last-minute addition to his monograph). N. mollis
is characterised by its very dense and particular indumentum, and by its lanceolate to spathulate-lanceolate leaves.
The identity of this taxon has been the subject of much conjecture, including suggestions that it might represent an
isolated example of a hybrid between e.g. N. fusca and N. hirsuta Hooker (1873: 99) (see Cheek & Jebb 2001) or that
it could be conspecific with N. hurrelliana Cheek & A.L.Lamb in Cheek et al. (2003: 118), a species described in 2003
but documented from at least as early as 1988 (Phillipps & Lamb 1988, Phillipps & Lamb 1996, Clarke 1997, Steiner
2002). The latter hypothesis was proposed following a comparison of herbarium materials of both taxa, whereupon it
was recognised that most key characteristics matched, the exception being the degree of leaf base decurrency and the
presence of bracts on the pedicels, the differences being postulated to be the result of natural variation across a wide
geographical range (Salmon 1999).
Our recent surveys of putative Nepenthes fusca and N. mollis on the Kemul Massif showed that the plants found
in situ match the deposited types, indicating a successful rediscovery of these two species after 93 years. Observations
of type N. fusca showed that this taxon is distinct from the two N. fusca s.lat. taxa found primarily in Sabah and
Sarawak (respectively), while in situ observations of Nepenthes mollis showed that this species is conspecific with N.
hurrelliana. An updated taxonomy of these taxa is provided here.

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Materials and Methods
To resolve the taxonomic uncertainties surrounding Nepenthes fusca and N. mollis, an expedition to the Kemul Massif
was carried out by the authors. It was deemed critical to ascend towards the highest point of the massif, the western
peak Batu Luye’u (meaning ‘Tiger Rock’ in the local Dayak Punan Aqut dialect), rather than the sub-peak to the east
reached by Endert in 1925 (1847 m; Fig. 1). This decision was made because the type of N. mollis (Endert 4282) is
pitcherless. Endert spent approximately a month on the flanks of Kemul and summited that eastern peak several times
(Endert 1927). As an experienced botanist who had five days prior collected N. fusca, Endert would have known to
collect Nepenthes material bearing pitchers—if present. Endert collected only pitcherless material, suggesting that
pitcher-bearing plants were not observed on any of his ascents of this peak. Since the N. fusca materials bear numerous
pitchers, we can infer that the absence of N. mollis pitchers was probably not due to unusually dry conditions, which,
as repeated recent El Niño years have highlighted, can lead to wholesale pitcher senescence throughout a population.
Instead, it is likely that the material was collected at the lower elevational range for N. mollis; many montane Nepenthes
are restricted to the very tops of mountains (see e.g., Clarke 1997, Clarke 2001a, McPherson 2009, Robinson et al.
2009) and often fail to pitcher when isolated individuals develop at sub-optimal elevations. It was thus hoped that the
highest ridges would provide the greatest odds of locating N. mollis in pitcher.
FIGURE 1. A map showing the location of the Kemul Massif with respect to the principal logistics access route from Wahau Baru town,
the expedition starting point (Long Sule village) and Mt. Bagong. Extents of geological terranes extracted from Tate (2001). Drawn by
A.S. Robinson.
In order to provide the significant food and safety equipment logistics needed to support the twelve-person
expedition team, the local coordinator (YS), and nineteen supporting indigenous Dayak Punan guides, it was necessary
for an advance group to transport cargo by road and river to the settlement nearest to the planned ascent route of the
Kemul Massif, namely the Dayak Punan village of Long Sule (North Kalimantan). This journey took AR, DG, NM
and BQ over a track that summits the geologically distinct (see Discussion) Mt. Bagong to the south, allowing for a
comparison of the flora between the two mountains and additional Nepenthes surveys.
The logistics team departed Wahau Baru (East Kutai Regency, East Kalimantan) on 23 June 2018, surveyed
the Nepenthes flora of Mt. Bagong from 27–28 June, and reached Long Sule on 29 June to await the arrival of the
remaining expedition team by air. The expedition team departed Long Sule on 02 July and successfully reached the
twin-peaked summit of Batu Luye’u (measured at ca. 2054 m) in the Kemul Massif on 07 July 2018 (Fig. 1).

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The ascent route of the Kemul Massif from Long Sule was plotted by AR using low resolution GIS topological
data exported from the United States Geological Survey EarthExplorer (earthexplorer.usgs.gov) and Google Earth Pro
(2018), providing a principal (southwestern) and a contingency (western) route to the summit along safe gradients
of ascent. YS generated a high resolution (1:50,000) topographical chart of the region from the NASA global digital
elevation model compiled from Shuttle Radar Topography Mission data (“SRTM V3.0, 1 arcsec”, NASA JPL 2014)
using ArcGIS 10.4 software, with contours set at 20 m intervals; stream lines set to include watercourses down to small
streams with flow accumulation values of >150 (using Arc Hydro Tools 10.3); and local place names gleaned during
a 2 year residency with the Dayak Punan at Long Sule. Comparing data sets, the plotted routes were deemed sound,
but the western route was designated the preferred route of ascent owing to the layout of stream lines; accessibility to
water was regarded as critical owing to the anticipated high-porosity limestone bedrock of the mountain.
All de novo georeferencing was made using a Garmin Oregon 600 GPS unit with dual GPS and GLONASS
telemetry enabled. Key measurements were made with a minimum of 5 averaged waypoint readings over the course
of a 20-minute period, with an estimated accuracy of ±2 m. An iPhone X served as a backup device, yielding almost
perfectly congruent data.
Maps were drawn by AR with Adobe Illustrator CC 2018 (Mac OS) using exported GIS and geological data
layers, GPS data collected during the expedition, and herbarium data as required.
The species descriptions are based on both field observations and examinations of herbarium specimens deposited
at BO, K, L, and SAR (acronyms follow Thiers 2019+). A stereo-microscope with a 1 mm graticule and side illumination
was used to document and measure small-scale structures such as hairs, nectar glands, and peristome ribs. In the case
of specimens whose lids were excessively recurved or otherwise unfavourably pressed, controlled applications of
small amounts of soapy water were made to render the lids pliable and allow for the manipulation necessary to examine
their abaxial surfaces.
All known archival documents belonging to Endert and relating to the 1925 expedition were reviewed by MG at
the Naturalis Biodiversity Center in Leiden, the Netherlands. This material comprises 13 large folders and includes
original notebooks, written correspondence, maps (both printed and sketched), newspaper clippings, and several
hundred original glass positives and negatives. Detailed inspection of all glass slides and corresponding documentation
revealed that Endert did not photograph any Nepenthes plants during the 1925 expedition, and that, therefore, the
appearance of live N. fusca s.str. and N. mollis remained completely undocumented.
Results
Nine different species of Nepenthes were observed during the expedition (Table 1, Fig. 2).
TABLE 1. Nepenthes taxa encountered on Mt. Bagong and the Kemul Massif, north-central Kalimantan.
Mount Bagong Nepenthes Elevation (m) Notes
N. chaniana 1300–1600 Terrestrial on clay laterite and sand washes adjacent to track. Not recorded
from Kalimantan
N. fusca s.lat. ‘Sarawak form’ 1100–1500 (–1900) Terrestrial on clay laterite. Widespread in Sarawak
N. hirsuta 1100 Few, terrestrial along sandstone ridge
N. lowii 1960–2110 Epiphytic on trees and terrestrial adjacent to track
N. reinwardtiana 1100–2100 Terrestrial, climbing strongly in trackside trees
N. tentaculata 1480 Terrestrial in humus in shady forest
N. sp. Bagong 1850–2110 Terrestrial to epiphytic in ridge forest and adjacent to track
Kemul Massif Nepenthes
N. fusca (type) 1400–1600 Terrestrial in humus pockets along a rocky ridge
N. lowii 2000–2054 Terrestrial and epiphytic in summit region only
N. tentaculata 1600–2054 Terrestrial and epiphytic in humus or moss pads
N. mollis (type) 1840–2054 Initially epiphytic, often terrestrial towards summit in humus or mossy banks
N. reinwardtiana 1450 Terrestrial in tuff on a rocky ridge

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FIGURE 2. Nepenthes documented during the expedition (all photographs taken in situ on Mt. Bagong and the Kemul Massif). Species
recorded on both Mt. Bagong and the Kemul Massif: A—N. lowii (plant from Kemul); B—N. reinwardtiana (Bagong); C—N. tentaculata
(Bagong); recorded on Mt. Bagong only: D—N. chaniana; E—N. fusca s.lat. ‘Sarawak form’ (named here as N. dactylifera); F—N. hirsuta;
G—N. sp. Bagong; recorded on Kemul Massif only: H—N. fusca s.str.; I—N. mollis. Photograph A by S.R. McPherson; B–I by A.S.
Robinson.

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Nepenthes species recorded on both Mt. Bagong and the Kemul Massif
Nepenthes reinwardtiana Miquel (1852: 168) and N. tentaculata Hooker (1873: 101), both of which are widespread
generalists over a range of elevations across Borneo (Clarke 1997, Cheek & Jebb 2001), as well as an unusual form
of N. lowii Hooker (1859: 420), a species otherwise known from Sabah, northern Sarawak and Brunei, and noted
for its mutualistic relationship with tree shrews (Clarke et al. 2009, Clarke et al. 2010). Though the latter taxon was
initially contemplated to represent the closely related N. ephippiata (from C. Kalimantan and E. Sarawak, Lee 2004)
on account of its atypical pitcher orientation, the diagnostic ephippium (after which N. ephippiata is named) was found
to be wholly absent from the climbing stems, while the pitcher waist and vestigial peristome are closer to N. lowii, and
the appendages within the lid cavity are not consistently reduced to tubercles in all upper pitchers as in N. ephippiata.
These almost intermediate characteristics are not surprising given the location of these peaks between the generally
accepted ranges of N. ephippiata and N. lowii, although why there should be graduation towards one form or the other
based on latitude is wholly unknown.
Nepenthes species recorded only on Mt. Bagong
Nepenthes chaniana Clarke, Lee & McPherson (2006: 56), known from Sabah and Sarawak primarily from mossy
forest on sandstone (Clarke et al. 2006, Cheek & Jebb 2001), but unusual in this case for producing pitchers 1/3 larger
(to ca. 35 cm tall excluding lids) and suffused with orange or red, rather than entirely yellowish-green or occasionally
red speckled as on Mt. Alab in Sabah and Batu Buli in Sarawak; N. fusca s.lat. ‘Sarawak form’, known mainly
from Sarawak where it is especially abundant on clay laterite road embankments in the Hose Mountains and Kelabit
Highlands at 1000–1300 m elevation (AR, MB, SM pers. observ.); and the widespread N. hirsuta, also typically found
on sandstone (Clarke 1997, Cheek & Jebb 2001). Also observed along summit ridges, either in humus overlying clay
and sand or in moss pads, was a Nepenthes taxon (N. sp. Bagong) that was initially considered a potential candidate for
N. mollis on account of its densely pubescent foliage and decurrent leaves (see Discussion).
Nepenthes species recorded only on the Kemul Massif
Nepenthes fusca s.str., found growing discontinuously in forest along the top of a narrow ridge, favouring brighter
situations with a more open canopy; and N. mollis, first sighted by Punan guides in the form of a large, fallen pitcher,
revealing a high epiphyte hanging from a bough ca. 20 m overhead identifiable by decurrent leaves on its 3 m pendent
stem, and soon after confirmed by examination of plants growing either terrestrially or on climbable trees in the
summit area.
Discussion
Floral assemblages
Exploration of the Kemul Massif and Mt. Bagong found unexpected differences in the structure of their forests.
Although many of the common Bornean montane tree genera were present on both mountains, including Shorea Roxb.
ex C.F.Gaertn. (Dipterocarpaceae Blume), Elaeocarpus L. (Elaeocarpaceae Juss.), Ficus L. (Moraceae Gaudich.) and
Lithocarpus Blume (Fagaceae Dumort.), the forests encountered along the route of ascent of the Kemul Massif were
found to be comparatively very open, with less dense understorey vegetation, greatly facilitating expedition progress.
At higher elevations on Kemul (1500–2054 m), there was also a greater preponderance of large Podocarpaceae Endl.,
including Dacrycarpus (Endl.) de Laub., Dacrydium Lamb., Phyllocladus Rich. ex Mirb., and Podocarpus L’Hér.
ex Pers., as well as Agathis borneensis Warb. (Araucariaceae Henkel & W.Hochst.), Tristaniopsis whiteana (Griff.)
Peter G.Wilson & J.T.Waterh. (Myrtaceae Juss.), Castanopsis (D.Don) Spach (Fagaceae) and, notably, an isolated true
pine (Pinus L., Pinaceae Spreng. ex F.Rudolphi). Though acid-loving herbaceous plants were abundant in the high
elevation moss forest, calcicolous Ardisia Sw. (Primulaceae Batsch ex Borkh.), Didymocarpus Wall. (Gesneriaceae
Dumort.) and Paphiopedilum bullenianum Pfitzer (Orchidaceae Juss.) were observed on or atop vertical walls of
metamorphosed limestone. This strongly contrasted with the denser understorey of Mt. Bagong and shorter trees at
higher elevations, with a more pronounced transition towards the summit into elfin montane forest and scrub, including
Quercus L. (Fagaceae), Leptospermum J.R.Forst. & G.Forst. (Myrtaceae), numerous Rhododendron L. (Ericaceae
Juss.) species, Camellia lanceolata (Blume) Seem. (Theaceae Mirb. ex Ker Gawl.), Schefflera J.R.Forst. & G.Forst.
(Araliaceae Juss.), and herbaceous plants including Gynura Cass. (Asteraceae Bercht. & J.Presl), various terrestrial
or lithophytic orchids like Coelogyne Lindl., Dendrobium Sw. and Peristylus Blume (Orchidaceae), and a lithophytic
carnivorous bladderwort, Utricularia striatula Sm. (Lentibulariaceae Rich.).

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The differences in general floral makeup seem to be reflected somewhat in the Nepenthes flora of these neighbouring
peaks, particularly the terrestrial species. Though the authors note that the presence of a 4WD track across the length of
Mt. Bagong opens up considerable habitat for ruderal species of genera like Nepenthes, four of the primarily terrestrial
taxa found on Mt. Bagong were not observed in suitable habitats on the Kemul Massif despite three of them being
widespread in Borneo. While the topography of each mountain and its effects on orographic rainfall undoubtedly affect
local plant assemblages, striking differences in geology between the two mountains are likely to account for the rather
different forest compositions observed.
Mount Kemul is the easternmost peak of a mountain massif (Rutten 1947) whose main prominence runs east–
west across the present-day borders of North Kalimantan and East Kalimantan, and approximately 37 km north of
Mt. Bagong (ca. 2165 m), the highest peak in the locally named Pegunungan Dua-Lima range to the south (Fig. 1).
The mountain complexes are thought to have formed from the mid-Neogene period onwards (10−5 million years
ago), during a set of geological episodes that also resulted in the formation of Sabah’s Crocker Range, including Mt.
Kinabalu (Collenette 1964, Hall 2002). However, despite their relative proximity, the two prominences are geologically
distinct; the uppermost part of the Kemul Massif is derived from uplifted Oligocene limestone, and Miocene alkaline
granites, both of which are apparent along the expedition route at 1300–1500 m (rock thrusts and cliffs of limestone
and slate) and 1700–1850 m (talus slope of igneous rock) elevation respectively; whilst the Dua-Lima range, including
Mt. Bagong and much of the surrounding area, is derived from older sediments (Tate 2001) that mainly include clays
and sandstones, both of which have given rise to surface laterites and washes of quartzitic sand (AR, DG, NM, BQ
pers. observ.), in keeping with the known substrate preferences of N. chaniana, N. fusca s.lat. ‘Sarawak form’ and N.
hirsuta found there.
Observations of Nepenthes fusca
Plants matching the Nepenthes fusca type materials (at BO, K, and L), as well as the description and illustration
provided by Danser (1928), were first located at 1400 m a.s.l. on a steeply ascending ridge. Whilst clearly related
to the taxa currently included within N. fusca s.lat., it was apparent that the lids of the type N. fusca are flat, more
or less ovate and usually with only a basal keel, and are larger than the pitcher opening, becoming longer in the
upper pitchers but not showing pronounced marginal revolution. Taking into account this and other morphological
and ecological differences (Table 1), N. fusca s.lat. clearly represents a species complex from which we can separate
two well characterised taxa whose ranges are centred on Sarawak and Sabah. N. fusca s.lat. ‘Sarawak form’ is here
proposed as N. dactylifera spec. nov., while the name N. zakriana is reinstated from synonymy for the Sabah taxon
with an emended description (see Taxonomy). A comparison of the upper pitchers of each species is provided (Fig. 3)
and their approximate ranges in Borneo indicated (Fig. 4).
FIGURE 3. Comparison of the upper pitchers of (A) Nepenthes fusca, (B) N. dactylifera (two pitchers) and (C) N. zakriana. Illustrated
by M. Barer.

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FIGURE 4. Distribution of Nepenthes dactylifera, N. fusca and N. zakriana in Borneo based on accessions held at BO, K, L and SAR
herbaria, supplemented by field observations. Drawn by A.S. Robinson.
Observations of Nepenthes mollis
Plants matching the Nepenthes mollis type material (at BO), as well as the description provided by Danser (1928),
were located from 1840 m a.s.l. Identity was determined by examination of the leaves, stems, indumentum, and male
inflorescences. Observations of living material bearing pitchers satisfied all authors that this taxon is conspecific with
N. hurrelliana, as hypothesised by Salmon (1999), making the name N. hurrelliana a later heterotypic synonym of
N. mollis. Additional measurements of living material at the type locality were made in order to provide an emended
and more representative circumscription of this species. The discrepancies between N. hurrelliana and the type material
of N. mollis raised by Salmon (1999) are addressed following the emended description of N. mollis (see Notes).
Observations of Nepenthes mollis at the type locality ruled out the initial belief that Nepenthes sp. Bagong might
represent N. mollis. The pitchers and laminae of the two taxa are very similar, however requisite comparisons of the
plants indicate that they represent a pair of closely related species that diverge markedly in terms of their petioles,
axillary buds, lids, stems and general stature, but particularly their inflorescences (summarised in Table 2). In fact,
Nepenthes sp. Bagong represents an undescribed taxon that has been documented across eastern Sarawak; including
only records for which clear photographic evidence or collections are immediately available to the authors, this taxon
has also been recorded from Batu Lawi (Jean De Witte pers. comm. 2003) and Batu Buli (Martin Dančák pers. comm.
2009), both in the Kelabit Highlands, as well as on Mt. Mulu (ca. 1400 m on the Melinau stream trail, AR, BQ pers.
observ. 2014) and in the Hose Mountains (MB pers. observ. 2016). Its known range thus includes peaks across an area
of 39,000 km2, but with only a few specimens noted at each locality, it remains a poorly-documented taxon.

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TABLE 2. A morphological comparison of Nepenthes dactylifera, N. fusca, and N. zakriana.
Nepenthes dactylifera Nepenthes fusca Nepenthes zakriana
Rosette leaves Broadly obovate to elliptic, base
abruptly attenuate, apex obtuse to
truncate
Obovate to sub-elliptic, base
gradually attenuate, apex obtuse to
emarginate
Elliptic to obovate, base gradually
attenuate, apex acute to obtuse
Vining stem leaves Oblong to elliptic, apex acute to
acuminate, adaxial surface with
sparsely scattered glands
Elliptic, apex obtuse, occasionally
acute
Narrowly elliptic to elliptic, rarely
obovate, apex acute
Leaf base decurrency Base decurrent into two narrow
wings 1–3 mm wide down entire
internode (but up to ca. 1.3
internodes, e.g. Prance 30548)
Not decurrent, base amplexicaul,
clasping stem by ca. 1/2 its dia.
Not decurrent to slightly
so, usually by <8 mm, base
amplexicaul by ca. 1/2–4/5 stem
dia.
Lower pitcher shape Ellipsoid in the lower half,
cylindric and slightly narrower
above, widening towards mouth,
peristome oblique, somewhat
uniform in width and strongly
raised at rear to form a neck
Sub-cylindric, slightly narrowed at
the midpoint with slight gibbosity
below the mouth, peristome
strongly oblique, widening from
midpoint of mouth towards raised
and slightly recurved neck
Cylindric to sub-ellipsoid
throughout or narrowly ellipsoid
in lower half and cylindric above,
often narrowing slightly towards
mouth, peristome oblique,
typically wider towards raised
neck, neck often recurved forwards
over mouth
Lower pitcher lid Narrowly ovate, usually
complanate, pronounced abaxial
midline rib with slight basal bulge
but no keel, distal part with few,
large crateriform glands, rarely
with terminal protuberance
Ovate, base sub-cordate, adaxial
surface typically channelled
along midline rib, abaxial rib only
slightly pronounced, but with
large basal keel bearing rounded
glands, abaxial surface with small
scattered glands and fine brown
hairs to 0.5 mm long
Ovate to sub-triangular, margins
sinuate, occasionally revolute,
abaxial midline rib pronounced
with large basal keel, distal
part sometimes with apical
protuberance up to 3 mm long,
bearing small crateriform glands
Upper pitcher shape Generally tubulose to broadly
infundibular, rarely narrowly
infundibular, peristome broad and
strongly oblique, pitchers often
large (15–25 cm tall)
Narrowly infundibular throughout,
peristome robust, often slightly
raised at front between wings,
slightly oblique thereafter then
rising more or less vertically to
form a slightly recurved neck
Generally infundibular with
prominent ventral gibbosity
below peristome, rarely narrowly
infundibular throughout, peristome
± horizontal at front, rising sharply
towards rear into neck, neck often
recurved over mouth
Lid shape in upper
pitchers
Very narrowly ovate to triangular,
appearing sagittate to ligulate due
to revolution or conduplication
of margins about 2/5 from base,
thereafter usually complanate
Ovate, base cordate, flattened,
margins sometimes sinusoid,
longer and broader than in lower
pitchers
Narrowly triangular-ovate,
appearing ligulate due to revolute
margins
Lid length in upper
pitchers
3.5–6.5(–7.5) cm long, generally
>4.5 times longer than wide
4.5–6.5 cm long, generally 1.8–2
times longer than wide
1.5–3.8(–5) cm long, generally
>4.5 times longer than wide
Lid appendages in
upper pitchers
Pronounced abaxial midline
rib, slight basal bulge or keel,
rib extending into an apical
protuberance 3–8 mm long
Abaxial midline rib only slightly
pronounced, but with a pronounced
basal keel, few to no glands,
usually with marginal hairs
Abaxial midline rib with
pronounced basal keel, apex with
or without apical protuberance up
to 3 mm long
Lower lid surface in
upper pitchers
Distal 2/3 of abaxial mid line rib
and protuberance with very large,
scattered crateriform nectar glands,
abaxial surface of lid densely
scattered with smaller nectar
glands
Indumentum of brown hairs on
both surfaces, to 0.5 mm long, but
up to 1 mm along lower edge of
keel
Crateriform glands sometimes
present along abaxial midline rib,
small nectar glands present across
abaxial surface
Indumentum of floral
parts
Glabrous to sparsely pubescent Raceme, pedicels and abaxial
floral parts densely pubescent
Generally pubescent
Elevation (300–)800–1500(–1900) m 1400–1600 m (800–)1200–2500 m
Growth habit Predominantly a high epiphyte
at lower elevations, frequently a
ruderal terrestrial in clay laterite
above 1200 m
Exclusively terrestrial in humus on
rocky, freely draining ridges
Predominantly epiphytic, but
occasionally terrestrial above 1300
m, favouring serpentine rubble or
humus banks

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Taxonomic treatment
1. Nepenthes dactylifera A.S.Rob., Golos, S.McPherson & Barer, spec. nov. (Figs. 5−6)
Type:—Borneo, Brunei, Temburong, Amo, Bukit Belalong, 4.33°N 115.09°E, 869 m a.s.l., 24 February 1992, Prance 30548 (holotype K!,
iso- L!) [K—climbing stem with upper pitchers; L—climbing stem with upper pitchers, infructescence].
− Nepenthes sp. [“undescribed species collected from the Mulu area”] in Phillipps & Lamb (1988: 8, 1 fig.).
− Nepenthes sp. A in Clarke (1997: 141, fig. 97) and Steiner (2002: 112).
− Nepenthes fusca auct. non Danser [Jebb & Cheek (1997: 41), partim; Cheek & Jebb (2001: 64), partim; Phillipps et al. (2008: 121),
partim [figs. 151, 154−155]; McPherson (2009: 346), partim].
Diagnosis:—Nepenthes dactylifera differs from N. fusca in the long-decurrent leaf bases (vs. non-decurrent), upper
pitchers tubulose to broadly infundibular (vs. narrowly infundibular), and upper pitcher lids very narrowly ovate,
appearing sagittate to ligulate through marginal revolution (vs. ovate and ±complanate).
Description:—Epiphytic or terrestrial scrambling, climbing or pendent shrub, to 4 m tall. Stems of rosettes terete,
0.6–0.9 cm in diameter, internodes 0.3–1.1 cm long; vining stems ca. 0.8 cm in diameter, internodes 6–12 cm long.
Leaves of rosettes coriaceous, petiolate, lamina broadly obovate-oblong to elliptic, 8–12 cm long, 5.5–8.5 cm wide,
apex obtuse to truncate, not peltate, base abruptly attenuate, petiole canaliculate, 3.5–5.5 cm long, sheathing and
clasping stem for >3/4 of its circumference. Longitudinal veins 2–3 on either side of midrib, restricted to outer third of
lamina, where they run parallel to the laminar margin, somewhat inconspicuous. Pinnate veins numerous, irregularly
reticulate, indistinct. Leaves of tall stems coriaceous, petiolate, lamina oblong to elliptic, 12–18 cm long, 6.5–9.5 cm
wide, adaxial surface with sparsely scattered glands, apex acute to acuminate, occasionally obtuse, base abruptly
attenuate, obtuse, petiole canaliculate, 4.5–6.5 cm long, base decurrent into two narrow wings, each 1–3 mm wide,
decurrent for 1–1.3 internodes. Tendrils to 35 cm long. Lower pitchers ellipsoid in the lower half, cylindric and slightly
narrower above, widening towards mouth, 8–16 cm tall, 2–3.5 cm wide, with fringed wings 2–4 mm wide, fringe
elements ≤6 mm long, 2–5 mm apart; peristome oblique, somewhat uniform in width and strongly raised at rear to
form a neck, 2.5–4 mm wide at front of pitcher, ribs very fine, ca. 0.2–0.4 mm apart, teeth minute. Lid narrowly ovate,
usually complanate, 2.5–3.5 cm long, 1.4–1.8 cm wide, with a pronounced abaxial midline rib and slight basal bulge
but no keel, distal part with few, large crateriform glands, rarely with terminal protuberance, abaxial surface of lid with
scattered crateriform glands 0.2–0.4 mm in diameter. Spur filiform, ca. 0.8–1.2 cm long. Upper pitchers tubulose to
broadly infundibular, rarely narrowly infundibular, 15–25 cm tall, 4.5–6.5 cm wide, wings absent or reduced to ridges;
peristome broad, 4–8 mm wide at front of pitcher, and strongly oblique, sometimes slightly raised at the front, ribs and
teeth as per lower pitchers. Lid very narrowly ovate to triangular, appearing sagittate to ligulate due to revolution or
conduplication of margins about 2/5 from base, thereafter usually complanate, 3.5–6.5(–7.5) cm long, generally >4.5
times longer than wide, with pronounced abaxial midline rib, slight basal bulge or keel, rib extending into an apical
protuberance 3–8 mm long; distal 2/3 of abaxial rib and protuberance with nectar glands scattered, narrowly elliptic,
very thickly bordered, ocellate-crateriform, ca. 1–1.5(–2) by 0.5(–1) mm, abaxial surface of lid densely scattered with
smaller ±circular, thinly bordered, crateriform nectar glands, ca. 0.3–0.6 mm in diameter. Spur filiform, 0.8–1.2 cm
long. Male inflorescence to 40 cm long, ca. 180 flowers, peduncle 10–15 cm long, 4–5 mm in diameter at the base,
rachis 15–25 cm long, partial peduncles 2-flowered, bifurcating 1–2 mm from base, bracts absent, pedicels to 0.8–1.2
cm long at base of rachis; tepals green, suffusing red once opened, broadly elliptic, 3–3.5 mm long, 2–2.5 mm wide,
apex more or less obtuse; staminal column 2 mm long, anther head to 2.5 mm in diameter, consisting of eight fused
anthers. Female inflorescence to 30 cm long, ca. 30–50 flowers, peduncle 15–20 cm long, ca. 5 mm in diameter at
the base, rachis 8–12 cm long, partial peduncles 2-flowered, lowermost sometimes with filiform bracts to 6 mm long,
tepals elliptic, ca. 3 mm long, 1.5–2 mm wide, apex acute, ovary ovoid, 4 mm tall, to 2.5 mm in diameter, fruit 1.5–2.5
cm long, seeds filiform, ca. 1.2 cm long, pale brown. Indumentum of short, fine brown hairs to ca. 0.5 mm scattered
over exterior surface of pitchers, tendrils, abaxial midrib and leaf margins, as well as petioles of rosette leaves and all
juvenile foliage, stem more or less glabrous, especially in tall stems. Inflorescences sparsely to densely pubescent, with
simple, reddish-brown woolly hairs present on the main axis, pedicels and abaxial surface of tepals. Colour variable,
mature stems usually reddish to black, leaves bright green, sometimes suffused with red, lower pitchers often dark,
olive green blotched with deep red or black, peristome green to deep red, often suffusing to pale green on inner margin,
upper pitchers from entirely pale green (almost white) to green blotched with red or, typically, green suffused with
orange with a whitish peristome striped with deep red.

REVISIONS IN NEPENTHES Phytotaxa 392 (2) © 2019 Magnolia Press • 107
FIGURE 5. Nepenthes dactylifera A.S.Rob., Golos, S.McPherson & Barer. A—climbing stem with emerging inflorescence. B—detail of
internode showing leaf base decurrency. C—lower pitcher. D—abaxial surface of lid of lower pitcher with crateriform glands. E—detail
of crateriform glands along midline rib as well as adjacent scattered pitted glands. F—upper pitchers, left lateral view, right ventral view.
G—lateral view of upper pitcher lid. H—detail of upper lid apical protuberance. I—inflorescence. J—seed capsules. K—male flowers.
Scale bars: A, B, C, D, F, G, J = 1 cm, E, H, K = 5 mm, I = 2 cm. Based on Prance 30548, as well as on photographs and measurements
made of in situ material. Illustrated by M. Barer.

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108 • Phytotaxa 392 (2) © 2019 Magnolia Press
FIGURE 6. Pitchers of Nepenthes dactylifera. A—lower pitcher (Kelabit Highlands). B—lower pitcher (Hose Mountains). C—upper
pitcher (Kelabit Highlands). D—upper pitcher (Hose Mountains). E—exposed clay laterite habitat (Hose Mountains). F—thinly bordered
crateriform nectar glands on abaxial lid surface. G—ocellate-crateriform glands in the apical region of an upper pitcher lid. F & G from
Prance 30548, grids = 1 mm. Photographs A–C by A.S Robinson; D, E by M. Barer; F, G by M.R. Golos.

REVISIONS IN NEPENTHES Phytotaxa 392 (2) © 2019 Magnolia Press • 109
Etymology:—The epithet dactylifera is derived from the Greek δάκτυλος (daktylos; finger) and the Latin suffix
-fer (bearing), a reference to the extremely long and narrow lid of this species, which fancifully resembles the arched
fingers of the Grim Reaper in popular culture.
Phenology:—Flowering and fruiting have been observed in the months of February, March, July, August,
September, and October.
Distribution and ecology:—Nepenthes dactylifera is widely distributed across the central highlands of Sarawak,
its range stretching the length of the state from at least the Second Division (e.g. Bukit Bangai) in the west to the Fifth
Division (e.g. Mt. Murud) in the east (Fig. 4). It has also been recorded from Brunei’s eastern exclave (Temburong),
from both North and East Kalimantan (Mt. Bagong), and from West Kalimantan (Mt. Keburau and Mt. Kenepai). It
grows mainly as a high epiphyte in trees from about 800 m a.s.l. but widely colonises ruderal habitats such as cleared
road cuttings generally above 1200 m, especially clay laterite sites in full sun. It is abundant on road embankments at
ca. 1300 m in the Kelabit Highlands and on logging roads in the Hose Mountains, Sarawak (AR pers. observ.). It is
only occasionally recorded above 1500 m elevation, such as on Mt. Bagong where isolated individuals were observed
during this expedition at 1900 m. At the other extreme it may grow as low as 300 m a.s.l. in hill forest (see Phillipps et
al. 2008: 127).
Nepenthes dactylifera is known to hybridise in nature with both N. platychila Lee (2002a: 257) and N. veitchii
Hooker (1859: 421) in the Hose Mountains (see Lee 2002a, Lee 2002b) and with N. vogelii Schuiteman & de Vogel
(2002: 537) in the Kelabit Highlands (AR pers. observ.).
Conservation status:—Nepenthes dactylifera is widespread in north-central Borneo above elevations of 800 m
and grows within a number of protected areas, including Ulu Temburong NP in Brunei, and Batang Ai NP, Gunung
Buda NP, Gunung Mulu NP and Pulong Tau NP in Sarawak. It is also likely to be present in the large Kayan Mentarang
NP in North Kalimantan, which runs along the border with Sarawak and Sabah. It therefore qualifies as Least Concern
when evaluated against the IUCN 3.1 criteria (IUCN 2012).
Notes:—The ocellate crateriform glands observed on the apical protuberance of the lid of the upper pitchers (Fig.
6G) are variable in size, but they can be exceptionally large, in some cases exceeding 2 mm in width and 1 mm in gape,
rivalling those on the much larger appendages of Nepenthes appendiculata Chi.C.Lee, Bourke, Rembold, W.Taylor
& S.T.Yeo in Lee et al. (2011: 24). The glands were observed to be heavily frequented by ants on some plants, but not
on others, and ants were found to be a fairly common prey type on Mt. Bagong.
A taxon belonging to Nepenthes fusca s.lat. that closely resembles N. dactylifera has been recorded from Mt.
Lumarku in southern Sabah. This taxon differs in having unusually narrow, yellowish lower and upper pitchers (Clarke
1997: fig. 58, Phillipps et al. 2008: fig. 156). In the absence of representative herbarium material and detailed field
observations, it is treated as an incompletely diagnosed taxon here.
Additional specimens examined:—KALIMANTAN: Hallier 1716 (K! [4 sheets]), G. Kenepai [W. Kalimantan],
no elevation data, 30 December 1893 – 5 January 1894 [separate climbing stem, leaf and upper pitcher elements];
Schmutz 7288(a) (L!), Kalimantan Barat (W. Borneo), Mt. Keburau, 1000 m, 28 May 1989 [short stem with lower
pitcher, pitcherless climbing stem]. SARAWAK: Adam 2414 (ABD!), Miri, Mt. Mulu, 1000 m, 10 December 1987
[climbing stem with upper pitcher; originally identified as N. maxima, later as N. curtisii by J.H. Adam, 25/1/1991];
Collenette 838 (K! [2 sheets]), 2nd Div., Bukit Bangai, Sungai Lemanak, 3000 ft [=914 m], 22 October 1961 [rosettes
with lower pitchers]; Collenette 844 (K! [2 sheets]), 2nd Division, Bukit Bangai, Sungai Lemanak, 3000 ft [=914 m],
22 October 1961 [climbing stem with upper pitcher, female inflorescence, infructescence; climbing stem with upper
pitchers]; S. 19609 (Ashton) (K!, L, SAR!) Carapa Pila, Pila [Hose Mountains]/Mujong watershed, Balleh, 900 m, 7
April 1964 [K—climbing stem with upper pitchers; SAR—short stem with lower pitchers]; S. 33945 (Chai) (K!, KEP,
L, MO, SAN, SAR!), 2nd Division, Lubok Antu District, Lanjak-Entimau P.F. [Protected Forest], Bukit Sengkajang,
3200 ft [=975 m], 17 March 1974 [K, SAR—climbing stem with upper pitchers, infructescence]; S. 64997 (Yii et al.)
(K, L! [2 sheets], SAR!), Bintulu div., Tatau, Ulu Sg. Sangan, Bukit Kana, 700 m, 8 October 1994 [L—climbing stem
with upper pitchers, female inflorescence; pitcherless climbing stem with male inflorescence; SAR—climbing stem
with pitcher (largely missing), female inflorescence]; S. 65959 (Mohtar & Yii) (K, KEP, SAR!), Bintulu Division,
Bukit Lumut, 800 m, 24 September 1992 [SAR—climbing stem with lidless upper pitchers, male inflorescence]; S.
66985 (Yii et al.) (K, KEP, L, MO, SAN, SAR!), Bintulu Division, Tatau, Ulu Sg. Sangan, Bukit Kana, 820 m, 11
October 1994 [SAR—climbing stem with upper pitcher bearing very broad peristome]; S. 67027 (Yii et al.) (KEP,
SAR!), Bintulu Division, Tatau, Ulu Sg. Sangan, Bukit Kana, 800 m, 13 October 1994 [SAR—climbing stem with
upper pitcher]; S. 77568 (Pearce et al.) (SAR!), Ulu Engkari LEWS [Lanjak Entimau Wildlife Sanctuary], Bukit
Pininjau, 1150 m, 1 September 1998 [climbing stem with upper pitchers]; S. 87448 (Lee & Jong) (SAR! [2 sheets]),
Limbang, Gunung Murud, side of logging road, 4°00’N 115°33’43”E, 1298 m, 24 August 2005 [climbing stem with

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110 • Phytotaxa 392 (2) © 2019 Magnolia Press
upper pitchers, infructescence; leaf with lower pitcher]; S. 90479 (Lim & Lee) (SAR!), Marudi, Sungai Silat Basin, SW
ridge of Bukit Palutan, 2°48.00’N 115°01.33’E, 1100 m, 28 March 2003 [stem with short internodes and small laminae
but bearing typical upper pitchers].
The following specimens from the Bukit Robertson area were examined as part of the assessment of N. dactylifera,
but are incompletely diagnosed:—SARAWAK: S. 80625 (Julaihi et al.) (SAR!), Belaga, ulu sungai Danum, summit
of hill next [to] Bukit Robertson, 02°28’42[.]82”N 114°33’9[.]62”[E], 1100 m, 7 August 1999 [climbing stem with
upper pitchers]; S. 81064 (Julaihi et al.) (SAR!), Belaga, ulu sg[.] Danum, hill near Bukit Robertson, 02°28’7[.]10”N
114°34’2[.]98”E, 850 m, 9 August 1999 [stem with lower pitchers].
Notes on specimens examined:—The taxon from Bukit Robertson—represented by (Julaihi et al.) 80625
and 81064—is rather distinctive, having narrowly infundibular upper pitchers with a very narrow peristome and an
extremely narrow and densely hairy lid. Lower pitchers likewise have an unusually narrow peristome and lid. While
N. dactylifera shows considerable variability in these characters, their expression in the plants from Bukit Robertson
is extreme. Field studies are needed before a more definitive determination can be made, and we therefore treat this
taxon as incompletely diagnosed at present.
At the other end of the spectrum, N. dactylifera can be a very robust species with a very broad peristome, as
exemplified by (Yii et al.) 66985.
2. Nepenthes fusca Danser (1928: 288, fig. 6) descr. emend. A.S.Rob. & Golos (Figs. 7−8)
Lectotype (designated by Jebb & Cheek 1997: 41):—Borneo, Kalimantan, W. Koetai, G. Kemoel, ±1500 m, 12 October 1925, Endert 3955
(BO!, isotypes BO!, K!, L) [date incorrectly listed as 12 November in Jebb & Cheek (1997) and Cheek & Jebb (2001)] [lectotype
BO—climbing stem with lidless upper pitchers, male inflorescence; iso- BO—separate lidless upper pitcher and intermediate
pitchers, leaf and stem elements; K—climbing stem with upper pitcher, male inflorescence].
− Nepenthes veitchii? auct. non Hook.f. [Endert (1927: 277)].
Other concepts of Nepenthes fusca s.lat.:—From our concept of Nepenthes fusca are to be excluded those of Kurata
(1976: 48, pl. 13), Phillipps & Lamb (1988: 24, 3 figs.), Phillipps & Lamb (1996: 87, fig. 48), and Clarke (1997:
87, figs. 57–58), quae pro parte = N. fusca Danser & N. zakriana (J.H.Adam & Wilcock) J.H.Adam & Hafiza, as
well as those of Jebb & Cheek (1997: 41), Cheek & Jebb (2001: 64), Phillipps et al. (2008: 121, figs. 149–156), and
McPherson (2009: 346, figs. 183–185), quae pro parte = N. dactylifera A.S.Rob., Golos, S.McPherson & Barer, N.
fusca Danser & N. zakriana (J.H.Adam & Wilcock) J.H.Adam & Hafiza.
Moreover, our concept of Nepenthes fusca does not include: − “Nepenthes fusca subsp. apoensis” J.
H.Adam & Wilcock ex Jebb & Cheek (1997: 41), nomen nudum; quae = N. stenophylla Mast., material at K!: S. 35939
(Chai), Borneo, Sarawak, 4th Div., Baram District, Kelabit Highland[s], summit of Apo Dari, 1550 m, 17 November 1974
[climbing stem with upper pitchers, female inflorescence; annotated as N. fusca var. apoensis (sic) by J.H. Adam, 25/1/1991)].
− “Nepenthes fusca subsp. kostermansiana” J.H.Adam & Wilcock ex Jebb & Cheek (1997: 41), nomen nudum; quae ≡
N. epiphytica A.S.Rob., Nerz & Wistuba, material at L! and K! (type material of N. epiphytica—see under “Additional
specimens examined”).
Description1:—Terrestrial climbing or scrambling shrub, to 5 m tall. Stems of rosettes terete, 0.6–0.8 cm in
diameter, internodes 0.4–1.5 cm long; vining stems 0.4–0.6 cm in diameter, internodes 8–15 cm long. Leaves of
rosettes coriaceous, petiolate, obovate to sub-elliptic, 12–15 cm long, 4–5.5 cm wide, apex obtuse to emarginate,
base gradually attenuate, petiole narrowly canaliculate, 2–3.5 cm long, base amplexicaul and sheathing stem for ca.
1/2 its circumference, rarely more. Longitudinal veins 4 on either side of midrib in outer third of lamina, where they
run parallel to the laminar margin, originating at base of leaf, inconspicuous. Pinnate veins numerous, irregularly
reticulate, indistinct. Tendrils more or less equal in length to lamina. Leaves of climbing stems scattered to sub-
alternate, coriaceous, petiolate, rarely sub-petiolate, lamina elliptic, 10–16 cm long, 3.5–6 cm wide, apex obtuse,
occasionally acute, base gradually attenuate, petiole 1.5–4.5 cm long, base amplexicaul and sheathing stem for ca.
1/2 its circumference, rarely more. Longitudinal veins 2 either side of midrib in outer third of lamina, parallel with
laminar margin, indistinct. Tendrils equal or up to twice as long as lamina, typically curling once only. Lower pitchers
sub-cylindric, narrowing slightly in the middle, with slight gibbosity below the mouth, 9–16 cm tall, 2.5–4.5 cm wide,
with fringed wings 1–3 mm wide, fringe elements to 8 mm long, 3–5 mm apart; peristome strongly oblique, widening
1 This emended description is based on measurements made of N. fusca in situ in the Kemul Massif and on examination
of the type material deposited at BO and K.

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FIGURE 7. Nepenthes fusca Danser. A—climbing stem with emerging inflorescence. B—lower pitcher. C—intermediate pitcher. D—
base of lower/intermediate pitcher lid, showing detail of highly glandular keel. E—upper pitchers, top right ventral view, bottom left lateral
view. F—base of upper pitcher lid showing distribution of indumentum. G—lower pitcher lid, top adaxial surface, bottom abaxial surface.
H—peristome in cross-section. I—dehiscing seed capsules. J—male flowers. Scale bars: A, B, C, E, G = 1 cm, D, F, H, I, J = 5 mm. Based
on Endert 3955 (isotype K) and supplemented with photographs and measurements made of in situ material. Illustrated by M. Barer.

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112 • Phytotaxa 392 (2) © 2019 Magnolia Press
from midpoint of mouth towards raised and slightly recurved neck, 2.5–4 mm wide at front of pitcher, sub-cylindric in
section, broadening and increasingly flattened towards neck and ≤12 mm wide, ribs ca. 0.3–0.5 mm apart, teeth fine,
≤0.4 mm long. Lid ovate, ±complanate, base sub-cordate, 3.5–5 cm long, 1.8–2.5 cm wide, adaxial surface typically
channelled along midline, with abaxial midline rib only slightly pronounced, but with pronounced semi-circular basal
keel 3–5 mm tall, bearing rounded glands and appearing bumpy, abaxial surface of lid with small, densely scattered
pitted circular glands and fine brown hairs to 0.5 mm long, apex slightly retuse, no apical protuberance but frequently
with a patch of sub-apical ocellate-crateriform glands. Spur filiform, simple, rarely branched at base into 2(–3) parts,
6–8 mm long. Upper pitchers narrowly infundibular throughout, 12–18 cm tall, 2.5–5.5 cm wide at mouth, wings
reduced to prominent ridges, with slight ventral flattening in between; peristome robust, 4–6 mm wide at front of pitcher
and flattened, usually slightly raised at front between wings, slightly oblique thereafter and increasingly cylindric,
rising more or less vertically to form a slightly recurved neck and widening to ≤15 mm wide. Lid ovate, base cordate,
±complanate, margins sometimes sinusoid, longer and broader than in lower pitchers, 4.5–6.5 cm long, generally 1.8–2
times longer than wide, abaxial midline rib only slightly pronounced, but with a pronounced basal keel, keel semi-
circular, 2–4 mm tall, bearing few inconspicuous to no glands and usually with brown, woolly hairs 0.8–1 mm long
along lower margin, shorter and sparser on appressed surfaces either side, distal part of midline rib sometimes with
longitudinally distended crateriform glands, apex usually diminished and without apical swelling, rarely with minute
apical protuberance ca. 1 mm long, indumentum of short, simple, brown hairs on abaxial and adaxial surfaces of lid, to
0.5 mm long. Spur filiform, simple or branched at base into 2 parts, 0.8–1.2 cm long. Male inflorescence to 20 cm long,
ca. 60–80 flowers, peduncle ca. 6–8 cm long, 4–5 mm in diameter at the base, rachis 8–12 cm long, partial peduncles
1- to (mainly) 2-flowered, bracts absent, bifurcating 0.5–1 mm from base, pedicels ca. 9 mm long; tepals green, distal
2/3 suffused with purple-red, elliptic, 3–3.5 mm long, 2 mm wide, apex acute, adaxial surface with 40–50 conspicuous
glands, typically green; staminal column to 2–3 mm long, anther head 1.8 mm in diameter, consisting of 8 fused
anthers, anthers red, pollen grains yellow. Female inflorescence to 18 cm long, peduncle 8–12 cm long, rachis 6–8 cm
long, partial peduncles 2-flowered, pedicels 5–7 mm long, tepals narrowly elliptic, ca. 2.5 mm long, apex acute, fruit
1.5–2.2 cm long, seeds filiform, 7–9 mm long, pale brown. Indumentum of rufous simple and branching hairs present
on stems, petioles, leaf margins and both surfaces of midrib, especially dense on emerging foliage and rachis, laminae
with simple, minute white hairs on adaxial surface, becoming somewhat caducous in mature leaves, and simple, sparse,
rufous hairs on abaxial surface and on pitchers. Colour of mature stems, leaves and tendrils green, developing foliage
flushed red or bronze, pitchers pale green (lowers) to yellowish green (uppers) and spotted externally and internally
(within the waxy zone only) with red to purple blotches, peristome colour as per pitchers with variable amounts of red
striation.
Phenology:—Male and female plants were observed in flower and fruit in July 2018, while the type materials
(all male) were collected in October. The region is not strongly seasonal and it is possible that flowering occurs
spontaneously throughout the year.
Distribution and ecology:—Nepenthes fusca was observed from 1400–1600 m a.s.l. on narrow, rocky, free-
draining ridges amidst relatively open ridge forest including small-trunked Elaeocarpus, Phyllocladus, and Tristaniopsis,
alongside various grasses, shrubs and the resam fern Dicranopteris linearis (Burm.f.) Underw.. All observed plants
were terrestrial in rocky humus banks or pockets of humus at the bases of trees, in breezy conditions that led to
significant drying of surface moisture during the day. Although these observations do not rule out an epiphytic habit
for N. fusca, no epiphytic plants were observed in damper forest away from the drying ridge-top conditions. This is in
contrast with N. dactylifera and N. zakriana, which are occasionally found growing as epiphytes in sheltered situations
close to where terrestrial plants are noted. In the absence of evidence to the contrary, N. fusca is regarded as a terrestrial
species, as per Danser (1928).
Although Nepenthes tentaculata occurs close to the upper elevation limits of N. fusca, no hybrids between the two
species were observed.
Conservation status:—Nepenthes fusca clearly has a restricted distribution, being thus far known only from
the Kemul Massif, with no equivalent material being noted by this expedition on Mt. Bagong to the south, where N.
dactylifera was present. However, in the absence of further explorations of the massif and adjacent mountains to the
north and west, the species must be listed here as Data Deficient (DD; IUCN 2012). The remoteness of the massif and
great expense of access present good barriers to unscrupulous collection; coupled with the low value of the plant, N.
fusca is unlikely to be meaningfully threatened by the horticultural trade.
Notes:—The overall characteristics of Nepenthes fusca, but especially its flattened lid, peristome and its general
colouration, resemble N. platychila and N. vogelii. Taking into account its basal lid appendage and mainly 2-flowered
partial peduncles, it appears close to N. epiphytica Robinson, Nerz & Wistuba (2011: 36), a species currently known

REVISIONS IN NEPENTHES Phytotaxa 392 (2) © 2019 Magnolia Press • 113
from only two limestone peaks in East Kalimantan (Robinson et al. 2011), which differs in being apparently exclusively
epiphytic, producing lids bearing a greatly reduced but nonetheless glandular basal swelling, and for its very widely
flaring upper pitchers. In common with N. mollis, the basal keels in the lids of the upper pitchers of N. fusca were found
to be hairy, with few to no glands, contrasting with those of the N. fusca lower pitchers, which appear bumpy as they
are covered with large, rounded glands.
Syrphid flies were observed on the male inflorescences of Nepenthes fusca, suggesting that they might represent
a pollinator. Muscid flies were also observed feeding on the basal keels of upper pitchers, although ants were found to
be the primary prey caught within the pitchers.
FIGURE 8. Nepenthes fusca. A—lower pitcher. B–C—upper pitchers. D—detail of male partial peduncles showing red thecae. E—aerial
camera view of the western flanks of the Kemul Massif. Approximate elevations for the main habitats of N. fusca (1400 m) and N. mollis
(2000 m) are indicated. Photographs A, B by A.S. Robinson; C–E by M.R. Golos.
Additional specimens examined:—Nepenthes epiphytica:—KALIMANTAN: Kostermans 21495 (holotype L!,
iso- K! [2 sheets]), Indon. E. Borneo [East Kalimantan], Berau, Mt. Njapa on Kelai R. limestone, 1000 m, 25 October
1963 [L—climbing stem with upper pitchers; annotated as N. fusca var. kostermaniana (sic) by J.H. Adam, 25/?/1991;
K—climbing stem with upper pitchers, female inflorescence; climbing stem with upper pitchers, infructescence].

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The following specimens were examined as part of the assessment of N. fusca s.lat., but are incompletely
diagnosed: SARAWAK: Anderson 218 (K!), Gunong Rumput, no elevation data, August 1912 [stem with lower and
upper pitchers]; B. 2791 (Burtt & Woods) (SAR! [2 sheets]), First Division, Poi [Pueh] Range, Gunong Berumput [=G.
Rumput], 4870 ft [=1484 m], 12 August 1962 [separate pitcherless stem, leaf, infructescence and male inflorescences;
climbing stem with upper pitchers]; Beccari 2386 (K!), locality given only as “Sarawak”, no elevation data, November
1871 [short stem with lower pitchers]; Beccari 2387 (K!), locality given only as “Sarawak, Borneo”, no elevation
data, collected 1865–1868 [stems with upper pitcher]; (Clemens & Clemens) 20233 (SAR!), Mt. Poi [=G. Pueh],
4500 ft [=1372 m], September 1929 [climbing stem with upper pitcher]; Jacobs 5115 (K!, L, SAR!), 1st div., N.
slopes of Mount Penrissen (S. of Kuching), approx. 1°5’N 110°15’E, 1000–1200 m, 7 August 1958 [K—climbing
stem with upper pitcher, male inflorescence; SAR—short stem, separate leaf with upper pitcher]; S. 513 (“Museum
Collector”) (SAR! [2 sheets]), foot of Mt Penrissen, no elevation data, 24 November 1909 [stem with intermediate
pitchers; climbing stem with lidless upper pitcher]; S. 12645 (Smythies) (K! [2 sheets], L, S, SAR!), Lundu District,
G. Berumput [=G. Rumput], 4877 ft [=1487 m], 25 August 1960 [K—leaf with upper pitchers; climbing stem with
upper pitchers; SAR—climbing stem with upper pitchers]; S. 15654 (Smythies) (K!, SAR!), Lundu District, G. Pueh
Forest Reserve, S. Sebat Kechil/S. Tembaga ridge, 3700 ft [=1128 m], 5 November 1961 [K—climbing stem with
upper pitcher; SAR—short stem with lower pitchers]; S. 42609 (Paie) (SAR!), 2nd Division, S’ggang Road, 85th Mile,
Silantek Kiri, Ulu Sg., path to Gunong Silantek, 564 m, 27 August 1980 [climbing stem with upper pitchers]; (Vogel)
933190 (L!), near Padawan, Gunung Penrissen, 800 m, October 1993 [two upper pitchers detached from leaves].
Notes on specimens examined:—Anderson 218, Beccari 2386 and 2387, (Burtt & Woods) 2791, (Clemens &
Clemens) 20233, Jacobs 5115, (“Museum Collector”) 513, (Paie) 42609, (Smythies) 12645 and 15654, and (Vogel)
933190 all represent an unusually robust form of Nepenthes fusca s.lat. with somewhat flattened lids that is periodically
photographed in western Borneo from the mountains (>900 m) S and W of Kuching, Sarawak, especially around
the popular Borneo Highlands Resort and Mt. Rumput. Danser (1928) placed the Anderson, Beccari and “Museum
Collector” specimens of this taxon within N. maxima, and Cheek’s notes on the first two accessions, as well Lee’s on
the last, place them within N. fusca s.lat. We are unable to place this taxon within N. fusca s.str. owing to the atypical
lid morphology, long-decurrent leaf bases, and particularly robust pitchers, while the form of the lid would also exclude
it from N. dactylifera. In situ studies of this taxon are merited.
The isotype of Nepenthes fusca at L, cited by Cheek & Jebb (2001), is not found in the herbarium’s database and
could not be located by MG during a visit in January 2018. According to Cheek & Jebb (2001), it and the isotype at K
are the only two original sheets with intact upper pitcher lids.
3. Nepenthes zakriana (J.H.Adam & Wilcock) J.H.Adam & Hafiza (2006: 434, figs. 3−4) descr. emend. A.S.Rob. &
Golos ≡ Nepenthes curtisii subsp. zakriana J.H.Adam & Wilcock (1998: 151, fig. XXIIa–b) (Figs. 9−10)
Type:—Borneo, Sabah, Mt. Kinabalu, Mamut, 1100 m, 21 January 1988, Adam, Adam & Aliosman 2431 (holotype UKMB, iso- ABD).
− “Nepenthes stenoperculum” ined. [annotated on the specimen (Clemens & Clemens) 30980/31092, deposited at BO].
− Nepenthes fusca auct. non Danser Kurata (1976: 48), partim [pl. 13]; [Phillipps & Lamb (1988: 24), partim [3 figs.]; Phillipps & Lamb
(1996: 87), partim [fig. 48]; Jebb & Cheek (1997: 41), partim; Clarke (1997: 87), partim [fig. 57]; Cheek & Jebb (2001: 64), partim;
Phillipps et al. (2008: 121), partim [figs. 149–150, 152–153]; McPherson (2009: 346), partim [figs. 183–185]].
− Nepenthes maxima auct. non Reinw. ex Nees [Kondo & Kondo (1983: 110), partim [1 fig.]; Kondo & Kondo (2006: 121), partim [1
fig.]].
Description2:—Epiphytic or terrestrial climbing or scrambling shrub, to 3 m tall. Stems of rosettes terete, 0.4–0.6
cm in diameter, internodes 0.5–1.5 cm long; vining stems ca. 0.5 cm in diameter, internodes 6–15 cm long. Leaves of
rosettes coriaceous, petiolate, elliptic to obovate, 10–12 cm long, 2.5–4.5 cm wide, apex acute to obtuse, base gradually
attenuate into petiole, petiole 1.5–4 cm long, base amplexicaul and sheathing stem by 1/2 to 4/5 its circumference,
not decurrent to slightly decurrent for less than 8 mm. Longitudinal veins 2–3 on either side of midrib in outer third
of lamina, running parallel to the laminar margin, originating at base of leaf, inconspicuous. Pinnate veins numerous,
irregularly reticulate, indistinct. Tendrils ±2 times the length of the lamina, generally 15–20 cm long. Leaves of
climbing stems scattered, coriaceous, petiolate, lamina narrowly elliptic to elliptic, rarely obovate, 9–16 cm long,
3.5–5 cm wide, apex acute, base gradually attenuate, petiole 3.5–6 cm long, base amplexicaul, sheathing stem by 1/2
to 4/5 its circumference, not decurrent to slightly decurrent for less than 8 mm. Tendrils ±1.5–2 times the length of the
lamina, generally 12–20 cm long, often curling twice. Lower pitchers cylindric to sub-ellipsoid throughout or narrowly
2 The emended description is based on measurements made of herbarium specimens and in situ material, and is pro-
vided in order to supplement the incomplete description presented in Adam & Hamid (2006).

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ellipsoid in lower half and cylindric above, often narrowing slightly towards mouth, 12–16(–23) cm tall, 3–5 cm wide,
with fringed wings 2–3 mm wide, fringe elements to 7 mm long, 3–6 mm apart; peristome oblique, typically wider
towards raised neck, neck often recurved forwards over mouth, 3–5 mm wide at front of pitcher, sub-cylindric, slightly
flattened, increasingly so towards neck and broadening to 6–8 mm wide, ribs ca. 0.3–0.4 mm apart, teeth minute, ≤0.4
mm long. Lid ovate to sub-triangular, 3–5 cm long, 1–1.8 cm wide, margins sinuate, occasionally revolute, abaxial
midline rib pronounced, with semi-circular basal keel to 3.5 mm tall, distal part sometimes with apical protuberance
2–3 mm long, bearing ocellate-crateriform glands 0.5–0.8 mm in diameter, abaxial surface of lid with small, scattered,
pitted glands ca. 0.2 mm in diameter. Spur simple, 5–8 mm long. Upper pitchers generally infundibular with a prominent
ventral gibbosity below peristome, rarely narrowly infundibular throughout, 10–16(–19) cm tall, 4–6 cm wide, wings
reduced to prominent ridges, peristome sub-cylindric, somewhat flattened, 2–6 mm wide at front and ca. 1/3 wider
at rear, ±horizontal at front, rising sharply towards rear into neck, neck often recurved over mouth. Lid narrowly
triangular-ovate, appearing ligulate due to revolute margins, 1.5–3.8(–5) cm long, generally >4.5 times longer than
wide, typically 0.5–1 cm wide, abaxial midline rib with pronounced semi-circular basal keel, apex with or without
glandular apical protuberance up to 3 mm long bearing ocellate-crateriform glands, same glands sometimes present
along abaxial midline rib, small nectar glands present across abaxial surface. Spur simple, filiform, 4–12 mm long.
Male inflorescence to ca. 20 cm long, 30–80 flowers, peduncle 3–8 cm long, rachis 9–15 cm long, partial peduncles
2-flowered, pedicels ca. 0.8 mm long, tepals elliptic, 3–4 mm long, 2.5–3 mm wide, apex acute, staminal column 3–4
mm long, anther head 1.5 mm in diameter. Female inflorescence to ca. 28 cm long, 30–50 flowers, peduncle 5–12 cm
long, rachis 4–13(–20) cm long, partial peduncles 2-flowered, pedicels 0.8–1.2 cm long, tepals elliptic in shape, 3.5–5
mm long, 2.5–3 mm wide, apex acute, fruit 2.5–3 cm long, seeds filiform, 1.2–1.8 cm long, pale brown. Indumentum
variable, consisting of short, simple, rufous to white hairs present on stems, pitchers, leaf margins, abaxial leaf surfaces,
abaxial midribs, and on developing foliage, becoming caducous in some plants such that older stems and leaves may
appear sub-glabrous, generally denser and more persistent on inflorescences. Colour of stems and leaves green, new
foliage sometimes suffused with red, pitcher colouration highly variable, lower pitchers green, grey-green or yellow-
green, usually mottled red, purple or black, peristome green, yellow to almost black, typically striated with bands of
red or purple, but often of uniform colour, upper pitchers equally variable, externally solid yellow-green or with red to
purplish-brown blotches, peristome often striated yellow and red, occasionally wholly yellow or red.
Phenology:—Herbarium specimens of Nepenthes zakriana in flower exist for almost every month of the year,
suggesting that flowering may occur at any point in time for a given individual.
Distribution and ecology:—Nepenthes zakriana has been recorded with certainty only from Sabah, and chiefly
the Crocker Range (Fig. 4), with Mt. Kinabalu and surrounding areas being its locus classicus. A single, pitcherless
specimen from Sarawak’s Gunung Mulu National Park ((Jermy) 13253) is labelled as N. fusca and resembles N.
zakriana (lacking the decurrent leaf bases of N. dactylifera), but its laminae are broadly elliptic with obtuse apices and
abruptly attenuated bases, atypical for the species; more complete material would be needed to confirm the identity of
this taxon.
Nepenthes zakriana is generally found at elevations of 1200–2500 m, but occasionally down to 800 m. This
species appears to be predominantly epiphytic, but is often observed growing terrestrially above 1300 m, being ruderal
at sites like road cuttings and on serpentine rubble, but also occurring on natural humus and moss banks.
Like most Nepenthes, N. zakriana hybridises readily with its congeners. The literature records putative natural hybrids
between N. zakriana (under the name N. fusca) and the following species: N. burbidgeae Hook.f ex Burbidge (1882:
56) on Mt. Kinabalu and adjacent areas such as Mamut copper mine (AR, MG pers. observ., Lowrie 1983); N. lowii
on Mt. Alab (Phillipps et al. 2008; originally identified as N. lowii × N. pilosa Danser (1928: 355) by Clarke 1997)
and Mt. Trus Madi (Fretwell 2013); N. reinwardtiana near Mt. Kinabalu (S. Hirosi pers. comm., McPherson 2009;
N. naquiyuddinii Adam & Hamid (2006: 431) may represent this cross, per Phillipps et al. 2008); N. stenophylla
Masters (1890: 240) on Mt. Trus Madi (Phillipps et al. 2008) and Mamut copper mine (AR pers. observ., Thong 2006);
N. tentaculata on Mt. Alab (Phillipps et al. 2008); and N. rajah Hooker (1859: 421) in the Mt. Kinabalu area (Clarke
1997).
Conservation status:—Nepenthes zakriana occurs widely across the western highlands of Sabah and is found
in a number of protected areas including the Crocker Range NP and Kinabalu NP. It qualifies as Least Concern when
evaluated against the IUCN 3.1 criteria (IUCN 2012).

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FIGURE 9. Nepenthes zakriana (J.H.Adam & Wilcock) J.H.Adam & Hafiza. A—climbing stem. B—lower pitcher. C—abaxial surface
of lid of lower pitcher. D—upper pitchers, top right Mamut copper mine, bottom left, Mt. Trus Madi. E—abaxial surface of lid of upper
pitcher. F—cross section of peristome. G—inflorescence. H—dehiscing seed capsules. Scale bars: A, B, D, G, H = 1 cm, C, E, F = 5 mm.
Based on Beaman 9957 and Hobbs 17, and supplemented with photographs and measurements made of in situ material. Illustrated by M.
Barer.

REVISIONS IN NEPENTHES Phytotaxa 392 (2) © 2019 Magnolia Press • 117
FIGURE 10. Pitchers of Nepenthes zakriana. A—lower pitcher (Mamut copper mine). B—lower pitcher (Mt. Trus Madi). C—upper
pitcher (Mt. Trus Madi). D—upper pitcher (Mt. Alab). E—climbing stem with pitchers, showing non-decurrent leaf bases (Mamut copper
mine). Photographs A–E by A.S. Robinson.
Notes:—The name Nepenthes zakriana is applied to this taxon as it was validly published by Adam & Hamid
(2006) to describe type material collected from a well-characterised and representative population of N. fusca sensu
Kurata (1976) from Mamut copper mine (Mt. Kinabalu). However, the protuberant apical lid appendage cited by
Adam & Hamid (2006) as a key characteristic of N. zakriana cannot be regarded as a reliable diagnostic feature of
this species. Different plants within a single population may or may not produce apical appendages, while different
pitchers on a single plant can be equally variable—an inconsistency that can be verified at the type locality (AR, MG
pers. observ.), as well as on trails around the Kinabalu Park Headquarters, Mt. Alab and Mt. Trus Madi (AR pers.
observ.). However, other features (listed in Table 2) including leaf base decurrency, lid morphology, pitcher shape and
indumentum make it possible to distinguish readily between this taxon and the closely related N. dactylifera.
Additional specimens examined:—SABAH: Beaman 8178 (K!, L!; photo), Penampang District, Crocker
Range, Km 50.7 on Kota Kinabalu–Tambunan Road, 5°50’N 116°19’E, 1600 m, 2 January 1984 [K, L—climbing stem
with upper pitcher]; Beaman 8910 (K! [2 sheets]), Penampang District, Crocker Range, Km 51.8 on Kota Kinabalu–
Tambunan Road, 5°50’N 116°20’E, 1500–1600 m, 16 March 1984 [separate leaves and pitchers; pitcherless climbing

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stem]; Beaman 9957 (K!, L!; photo), Ranau District, Mamut Copper Mine, 6°02’N 116°39’E, 1600–1700 m, 30
May 1984 [K—climbing stem with upper pitchers, separate lower pitcher; L—leaf with lower pitcher, separate lower
pitchers]; (Clemens & Clemens) 30980/31092 (BO!), single sheet combining two labels: (30980) Upper Kinabalu,
Penibukan, near Table rock, left trail, north ridge, 5000 ft [=1524 m], 16 January 1933; (31092) Mt. Kinabalu,
Penibukan, ridge above Kina Taki river, 4000 ft [=1219 m], 16 January 1933 [climbing stem with upper pitchers,
infructescence; “N. stenoperculum MSC”—annotation by M.S. Clemens]; (Clemens & Clemens) 31570 (BO!), two
conflicting labels: (1) Mt. Kinabalu, Penibukan, 4000–5000 ft [=1219–1524 m], 7 February 1933; (2) Mt. Kinabalu,
Keebambang river, 4000 ft [=1219 m], 3 August 1933 [climbing stem with upper pitchers, male inflorescence];
(Clemens & Clemens) 34454 (BO! [2 sheets]), Mt. Kinabalu, Colombon basin, below Keebambang lobang, 3500 ft
[=1067 m], 14 August 1933 [climbing stems with upper pitchers]; (Clemens & Clemens) 50961 (K!), Upper Kinabalu,
7000–8000 ft [=2134–2438 m], 7 December 1933 [climbing stem with upper pitchers]; Collenette 815[a] (K!), Royal
Society Route [up Mt. Kinabalu], near platform 2 hrs above Base, 5275 ft [=1608 m], 16 August 1961 [separate leaf
and lower pitcher elements]; Collenette 815[b] (K!), Mt. Kinabalu, eastern shoulder, 4000–5000 ft [=1219–1524 m],
16 August 1961 [short stem with lower pitchers]; Collenette 816[a] (K!), Royal Society Route [up Mt. Kinabalu],
near platform 2 hrs above Base, 5275 ft [=1608 m], 16 August 1961 [leaf with upper pitcher]; Collenette 816[b] (K!),
Mt. Kinabalu, eastern shoulder, 4000–5000 ft [=1219–1524 m], 16 August 1961 [climbing stem with upper pitchers];
Comber 4031 (K!), Sapong, 3000 ft [=914 m], no date [climbing stem with upper pitchers, male inflorescences]; de
Vogel 8078 (L!), West Coast Residency, road Kimanis–Keningau, Crocker Range, on the watershed, 5°28’N 116°03’E,
1500 m, 6 October 1986 [stem with intermediate pitchers]; Hobbs 17 (K!), Trus Madi, SE ridge, 4500 ft [=1372 m],
22 August 1977 [pitcherless climbing stem and leaf with lower pitcher]; Hobbs 18 (K!), Trus Madi, SE ridge, 4500
ft [=1372 m], 22 August 1977 [short stem with lower pitchers]; Hobbs 72 (K!), Ranau, Mt. Kinabalu, 5500 ft [=1676
m], 26 September 1977 [climbing stem with intermediate pitcher, separate lower pitcher]; Hobbs 73 (K!), Ranau, Mt.
Kinabalu, 6500 ft [=1981 m], 26 September 1977 [short stem with lower pitchers]; Rickards 101 (K!), Mt. Kinabalu,
5400 ft [=1646 m], 19 June 1976 [short stem with lower pitchers]; Rickards 156 (K!), Mt. Kinabalu, 5500 ft [=1676
m], 20 June 1976 [short stem with lower pitchers]; RSNB 4377 (Chew & Corner) (K!), Bembangan River, 5000 ft
[=1524 m], 19 February 1964 [climbing stem with upper pitchers, male inflorescence]; RSNB 4415 (Chew & Corner)
(K!), Bembangan River, 5000 ft [=1524 m], 20 February 1964 [stems with lower pitchers]; SAN 60818 (Amin et al.)
(K!), Tambunan District, Gu. Alab Range, 600 ft [=183 m] [sic—clearly an error; the elevation of Mt. Alab is ca. 6200
ft (1900 m)], 21 July 1984 [climbing stem with upper pitcher, female inflorescence]; SAN 82759 (Lantoh) (K!, KEP,
L, SAR), Ranau District, Kinabalu Sabah National Park, 6000 ft [=1829 m], 26 January 1976 [K—climbing stem with
upper pitchers, male inflorescences]; SAN 91184 (Aban & Dewol) (K!, KEP, L, SAR, SING), Beluran District, Bukit
Liminintong, 2800 ft [=853 m], 9 April 1980 [K—short stem with lower pitchers]; SAN 91185 (Aban & Dewol) (BO,
K!, KEP, L, SAR, SING), Beluran District, Bukit Liminintong, 2800 ft [=853 m], 9 April 1980 [K—climbing stem
with upper pitcher, infructescence]; SAN 121014 (Amin et al.) (K!, L!), Ranau District, Bambangan, no elevation data,
10 September 1987 [K, L—climbing stem with intermediate pitcher]; SAN 127727 (Fidilis) (K!, L!), Penampang
District, Togudon/Tungol Km 48 Jalan Tambunan/Penampang, 1400 m, 14 August 1989 [K—two climbing stems: one
with upper pitcher, one pitcherless with male inflorescence; L—pitcherless climbing stem with infructescence]; SAN
147507 (Suzana) (K!, L!), Ranau, Mamut Copper Mine, 6°20’N 116°40’E, 1200 m, 29 November 2005 [K—climbing
stem with upper pitcher, female inflorescence; L—pitcherless climbing stem with female inflorescence]; Schwallier
60 (L!), Crocker Range, down main road [from] Alab Station, 5°49’4.09”N 116°20’23.16”E, 1836 m, 24 September
2012 [climbing stem with upper pitcher, male inflorescence]; Schwallier 61 (L!), Crocker Range, down main road
[from] Alab Station, 5°48’51.2”N 116°20’23.58”E, 1778 m, 24 September 2012 [climbing stem with upper pitcher,
female inflorescence (unopened flowers)]; Schwallier 62 (L!), Crocker Range, down main road [from] Alab Station,
5°48’52.38”N 116°20’23.82”E, 1764 m, 24 September 2012 [short stem with lower pitcher]; Schwallier 63 (L!),
Crocker Range, down main road [from] Alab Station, 5°48’52.38”N 116°20’23.82”E, 1764 m, 24 September 2012
[climbing stem with upper pitcher, inflorescence (unopened flowers)]. SARAWAK: (Jermy) 13253 (K!), Gunung
Mulu National Park, around Camp 3 [of Royal Geographical Society’s Expedition to Gunong Mulu 1977–78], 1150–
1250 m, 5 October 1976 [pitcherless climbing stem—in the absence of pitchers, the specimen is of limited value].
Nepenthes stenophylla:—SABAH: SAN 83146 (Cockburn) (K!, L), Lamag District, Inarat, S. ridge of Gunung
Lotung, 3000 ft [=914 m], 15 May 1976 [K—high epiphyte; climbing stem with upper pitcher, lid absent]; SAN
83251 (Cockburn) (K!, L), Lamag District, Inarat, S. slopes of Gunong Lotong [Maliau Basin], 4300 ft [=1311 m], 16
May 1976 [K—climbing stem with upper pitcher, infructescence]; SAN 151747 (Pereira) (L!), Ranau, west of Bkt.
Hampuan FR [Forest Reserve], 6°01’26”N 116°39’41”, 1489 m, 12 May 2010 [climbing stem with upper pitcher,
infructescence].

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Notes on specimens examined:—SAN 83251 (Cockburn) was labelled as Nepenthes cf. stenophylla but
subsequently identified as N. fusca by Smythies (20/12/1977) and Jebb (9/11/1993) on the sheet. However, the lid,
though partially folded, appears complanate and is noted to be as large as the pitcher opening, which is atypical of
N. fusca s.lat.—based on extensive exploration of the Maliau Basin, AR, SM and BQ determine that this material
represents the diminutive heath-forest form of N. stenophylla found throughout the Maliau Basin above elevations of
ca. 1000 m. SAN 83146 (Cockburn) is conspecific with this taxon. SAN 151747 (Pereira), identified as N. fusca by
Madani (7/2010), likewise represents N. stenophylla (det. AR & MG), which is widespread at the stated locality.
The isotype of Nepenthes zakriana at the University of Aberdeen Herbarium (ABD) could not be located despite
an extensive search of the collections; staff indicate that there are no records that it was ever deposited.
4. Nepenthes mollis Danser (1928: 338, fig. 14) descr. emend. A.S.Rob. & Golos (Figs. 11−12)
Type:—Borneo, Kalimantan, W. Koetai, G. Kemoel, ±1800 m, 17 October 1925, Endert 4282 (holotype BO!) [pitcherless climbing stem
with male inflorescence; single sheet labelled “Unicum!”].
= Nepenthes hurrelliana Cheek & A.L.Lamb in Cheek et al. (2003: 118, figs. 1–3), syn. nov.
Type:—Borneo, Sabah, Gunung Lumarku, August 1999, Lamb & Surat 145/99 (holotype SAN, iso- K).
− Nepenthes fusca × N. veitchii in Phillipps & Lamb (1988: 26, 1 fig.).
− Nepenthes sp. in Phillipps & Lamb (1996: 150, fig. 80) and Salmon (1999: 24, fig. 1).
− Nepenthes sp. B in Clarke (1997: 142, fig. 98) and Steiner (2002: 110, figs. 172–173).
Description3:—Epiphytic or terrestrial climbing or pendent shrub, to 5(–10) m tall. Stems of rosettes terete, 7–10
mm in diameter, internodes 0.6–2.5 cm long; vining stems ±terete, 5–9 mm in diameter, internodes 9–15 cm long,
axillary buds nodular, ca. 5–7 mm in diameter, 1–3 mm tall, 5–12 mm above the axil, occasionally apically filiform
to 5 mm. Leaves of rosettes coriaceous, petiolate, lamina obovate, becoming narrowly obovate to oblanceolate with
increasing internode length, 10–15 cm long, 3.5–5 cm wide, apex retuse, becoming acute, not peltate, base gradually
attenuate, petiole canaliculate, 2–3.5 cm long, not winged, not decurrent, sheathing and clasping the stem for its entire
circumference. Longitudinal veins (1–)2–3 on either side of midrib, restricted to outer third of lamina where they
run parallel to the laminar margin, inconspicuous. Pinnate veins numerous, irregularly reticulate, indistinct. Tendrils
ca. 1.5 times longer than the laminae, without curl. Leaves of tall stems coriaceous, initially petiolate and winged, to
5 cm long with wings 0.3–0.8 cm wide, sheathing stem for 3/5–4/5 its circumference, becoming sub-petiolate and
shortly decurrent to ca. 2 cm, thereafter sessile and strongly decurrent with ±parallel margins towards the base, lamina
oblanceolate to oblong-spathulate, (11.5–)14–20(–24) cm long, 3.5–5(–6.5) cm wide, apex acute, rarely sub-peltate,
to obtuse, base almost wholly amplexicaul, strongly oblique and decurrent into two wings for 2–5(–6) cm, usually
1/4–1/3 of total internode length, wings ca. 0.8–1.4 cm wide either side of stem, thereafter gradually attenuate into
stem, longitudinal veins 2(–3), inconspicuous in living material. Tendrils ca. 2 times longer than the laminae, typically
with 2.5 curls. Lower pitchers sub-cylindric, 9–15(–21) cm tall, 2–5.5 cm wide, with fringed wings 2–5 mm wide
throughout, fringe elements 3–7 mm long, 3–5 mm apart; peristome horizontal between wings, thereafter strongly
oblique, becoming vertical in the rear half and slightly recurved over pitcher opening towards lid, sub-cylindric at the
front, 3–7 mm wide, rear part flattened, ca. 5 times wider than at front, usually without marginal lobes, ribs pronounced
ca. 0.8 mm apart, teeth ca. 0.8–1 mm long. Lid ovate, complanate, base cordate, apex obtuse to retuse, 2.5–5 cm
long, 1.5–3 cm wide, with pronounced abaxial midline rib and a prominent keel, projecting 4–7 mm below lid and
hooked towards rear, keel minutely and densely glandular, glands crateriform, ca. 0.2 mm in diameter, and pubescent,
apical protuberance absent. Spur simple, filiform, 0.6–1.1 cm long. Intermediate pitchers sub-cylindric to slightly
infundibuliform, gradually widening from base to apex, 12–22(–30) cm long, 3.2–8 cm wide, with fringed wings in
the upper half, (0–)1–2(–5) mm wide, fringed elements 2–3(–7) mm long, 2–4 mm apart, or with wings occasionally
reduced to prominent ridges; peristome broad, often slightly raised between wings, front 1/2 to 2/3 near horizontal,
abruptly becoming vertical in the rear 1/2 to 1/3, forming a column 4–8(–12) cm tall, 3–15 mm wide at the front of
the pitcher, sub-cylindric, the raised, rear part flattened, up to 5 times wider than front of pitcher, outer edge sinuate,
shallowly 1–3–lobed, ribs strongly pronounced, 1–1.5(–2) mm apart, 0.3–1 mm high, teeth 1–1.5 mm long at the
front of the pitcher, 2–3.5 mm long on the column, where they project downwards at an acute angle into the mouth.
Lid triangular-ovate with a slightly cordate base, 2.5–8 cm long, 2–4 cm wide, apex rounded, lower surface with
pronounced basal keel projecting 8–10 mm below lid on a base about as long, strongly hooked towards rear, nectar
3This emended description incorporates details from the description of Nepenthes hurrelliana in Cheek et al. (2003),
observations of same in situ on Mt. Murud, the type description of N. mollis (Danser 1928), and measurements made
of N. mollis in situ in the Kemul Massif.

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120 • Phytotaxa 392 (2) © 2019 Magnolia Press
glands extremely dense on basal appendage and immediately adjoining part of lid, orbicular, 0.15 mm in diameter
with a thin, raised border, keel often slightly pubescent, abaxial surface of lid with thinly scattered smaller glands
mainly in the basal half, orbicular to shortly transversely elliptic, 0.15–0.25 mm long, often fewer or absent from
apical half, apical protuberance sometimes absent, otherwise umbonate-conic to filiform, to ca. 5 mm long, 1 mm in
diameter. Spur simple, filiform, 1–1.5 cm long, slightly recurved. Upper pitchers infundibular throughout, 18–24 cm
long, 6–9 cm wide just below the mouth, often abruptly constricted at peristome, wings reduced to prominent ridges;
form of peristome similar to intermediate pitchers, but 4–6 mm wide at front of mouth, rear, flattened part only up to
3.5 times wider than front of pitcher and usually slightly more cylindric, column 5.5–9 cm tall. Lid triangular-ovate
with a cordate base, 3.5–5 cm long, 2–3 cm wide, midline rib prominent with large, pubescent glandular keel and
usually with a 2–3 mm apical appendage with large pitted glands. Spur filiform, up to 25 mm long. Male inflorescence
20–27 cm long, 80–150 flowers, peduncle 6–9(–12) cm long, 3–4 mm in diameter at the base, rachis 10–15 cm long,
partial-peduncles 2-flowered, bifurcating 1–1.5 mm from the base, base with bract, linear, rarely bifurcated, patent to
ascending, 3–4 mm long, caducous, pedicels 7–10 mm long, tepals deep burgundy to green, elliptic, 3.5–4 mm long,
2–3 mm wide, deflexed and somewhat concave, adaxial surface with 30–40 deeply pitted glands, apex rounded to
acute; staminal column 2.8–3.5 mm long, anther head 1.5 mm in diameter, thecae and pollen grains yellow. Female
inflorescence 22–30 cm long, 40–70 flowers, peduncle 12–15 cm long, rachis 10–12 cm long, partial-peduncles 2-
flowered, 5–7 mm long, without bracts, pedicels 5–10 mm long, tepals elliptic, apex acute, 4–5(–6) mm long, ovary
sessile, ellipsoid, 5 mm long. Seed 10–12 mm long. Indumentum abundant, consisting of coarse, brown to rufous hairs,
partly shorter, branched and spreading, partly simple and up to 1.2–1.8 mm long, especially dense on young foliage,
the stem, leaf margins, the abaxial leaf surface, the abaxial midrib, basal adaxial midrib and on the tendril, as well as
more sparsely on the exterior surface of the pitchers, including the adaxial surface of the lid, and the abaxial surface
mainly on the basal keel. The indumentum of the adaxial leaf surface differs in being covered with short, simple,
whitish hairs. The inflorescences are densely pubescent with woolly, rufous hairs in the main axis, while the partial-
peduncles, pedicels, abaxial tepal surface, tepal margins and staminal column are covered with shorter, simple hairs.
Colour of mature stems usually green to olive green, lower pitchers often olive green to yellowish green, sometimes
blotched with deep red or purple, peristome purple to brown and striped with yellow or green, upper pitchers entirely
yellowish green to green blotched with red or suffused with deep red throughout.
Phenology:—Flowering was observed in Kemul Massif plants in early July. Flowering has been observed on Mt.
Murud (Sarawak) in July and October (AR pers. observ.).
Distribution and ecology:—Outside of north-central Kalimantan (Kemul Massif), Nepenthes mollis has been
recorded (and ascribed to N. hurrelliana) from Brunei (Bukit Pagon), southwestern Sabah (Mt. Lumarku, Meligan
Range), and northeastern Sarawak (Mt. Mulu, Mt. Murud) (Cheek et al. 2003, Phillipps et al. 2008). However, the
plants from Mt. Mulu are atypical in a number of respects (AR, BQ pers. observ., Phillipps et al. 2008); coupled with
the established presence of N. sp. Bagong on Mt. Mulu, it cannot be unequivocally stated here whether the plants in
the cited literature describe one taxon or the other without pointed investigation.
The known elevational range is that previously reported for N. hurrelliana: 1300–2400 m (Phillipps et al. 2008).
On Mt. Murud and the Kemul Massif, plants occur in high montane forest, persisting in relative shade but growing
most strongly in canopy breaks and more open areas. On Mt. Murud, where the expansive sandstone escarpment that
makes up the mountain emerges above 2100 m, plants also occur in exposed sites, occupying humus pockets within
a rocky, elfin forest habitat where its congeners N. lowii and N. murudensis Culham ex Jebb & Cheek (1997: 66)
predominate.
Nepenthes mollis has been documented (as N. hurrelliana) to form natural hybrids with N. chaniana and N.
lowii on Batu Buli (Phillipps et al. 2008, Scharmann 2010a, Scharmann 2010b) and also with N. veitchii (McPherson
2009).
Conservation status:—Though Nepenthes mollis is known from a relatively small number of mountains, these
span a wide area in north-central Borneo. Its range is therefore large and encompasses dozens of peaks of suitable
elevation that have not been explored or at least well botanised, making a wider distribution likely. Large populations
are afforded protection in Pulong Tau NP (Sarawak), with additional populations protected in Ulu Temburong NP
(Brunei). The remaining sites occur at high elevations on steep terrain unlikely to be subject to logging. The species
therefore qualifies as Least Concern when evaluated against the IUCN 3.1 criteria (IUCN 2012).
Notes:—Salmon (1999) recognised that the taxon that would be described as N. hurrelliana (Cheek et al. 2003)
matched the type material of N. mollis closely, noting two exceptions: that the leaf bases of the N. mollis type are
decurrent for 4–6 cm, while those of N. hurrelliana are decurrent for 1–2 cm; and that the pedicels of N. mollis (a male
inflorescence) lack bracts, while those of N. hurrelliana bear 3–4 mm long bracts at the base of the pedicels.

REVISIONS IN NEPENTHES Phytotaxa 392 (2) © 2019 Magnolia Press • 121
FIGURE 11. Nepenthes mollis Danser. A—rosette with right lower and left intermediate pitchers. B—climbing stem bearing upper
pitchers and male inflorescence, note increasing leaf decurrency. C—adaxial detail of a climbing stem leaf showing leaf attachment.
D—detail of leaf margin and adaxial surface. E—detail of upper pitcher lid, left adaxial surface, middle abaxial surface, right lateral view
showing keel. F—cross section of peristome. G—male flowers. H—dehiscing seed capsules. Scale bars: A, B, C, E, F = 1 cm, D, H =
5 mm, G = 2 mm. Based on Endert 4282 and supplemented with photographs and measurements made of in situ material. Illustrated by
M. Barer.

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122 • Phytotaxa 392 (2) © 2019 Magnolia Press
FIGURE 12. Pitchers and leaves of Nepenthes mollis. Top row Kemul Massif, middle row Mt. Murud. A & D—lower pitchers. B &
E—intermediate pitchers. C & F—upper pitchers. G—petiolate bases of rosette leaves (Kemul Massif). H—decurrent bases of climbing
stem leaves, abaxial perspective, and I—lateral perspective (both Kemul Massif). Photographs A, B, D, E, F, H by A.S. Robinson; C, I by
M.R. Golos; G by S.R. McPherson.

REVISIONS IN NEPENTHES Phytotaxa 392 (2) © 2019 Magnolia Press • 123
In addressing these inconsistencies, it is first necessary to better characterise Nepenthes hurrelliana. When the
species was described, it was relatively poorly known, the protologue (Cheek et al. 2003) notably describing the
“Rosette and short stems [as] unknown”. Since then, numerous excursions have been made to Mt. Murud to study N.
hurrelliana in situ (for example, 6 separate ascents of Murud have been made between AR and SM alone). Observations
have found that the leaves of plants in the rosette stage are strongly petiolate, lack wings and exhibit no apparent
decurrency; with increasing internode length, however, there is a shift towards the production of oblanceolate leaves
with winged petioles that are slightly decurrent, while in tall climbing stems the leaves become sub-petiolate to wholly
spathulate-lanceolate and decurrent for ca. 3–5 cm, that is, decurrent for approximately 1/3 of any given climbing
internode. This same progression was noted in N. mollis in the Kemul Massif and is documented in Fig. 12. This trait,
which is uncommon in Nepenthes, presents a particular problem of material consistency in terms of the specimens
collected for common reference, whereby the vertical position along the stem of the collected material affects not only
pitcher morphology but also the morphology of the leaf bases! Explorations of Mt. Murud have shown that there is
considerable variation in leaf decurrency according to the length of the stem, but moreover that there is overlap in the
degree of decurrency between N. hurrelliana in situ, the type material of N. mollis, and living specimens of N. mollis
observed in the Kemul Massif.
With regard to the floral inconsistencies, while measuring living male inflorescences of N. mollis in situ, it was
noted that bracts were present on the pedicels of many of the flowers, but not on all. Additionally, examination of
dead male inflorescences on the same plants found scant evidence of floral bracts. This suggests either that bracts are
produced inconsistently or, more likely, that the bracts might be caducous, which could explain the stated absence of
bracts from the type material. Surprisingly, examination of the N. mollis type material (Endert 4282) held at BO found
what appear to be several bracts towards the distal part of the damaged inflorescence, which suggests that these might
have been overlooked by Danser. Field observations show that bracts do appear to be more consistently produced in the
Mt. Murud population, but inconsistency in bract production has been noted between wild populations of other species
of Nepenthes, most notably N. robcantleyi Cheek (2011: 678) and Nepenthes graciliflora Elmer (1912: 1494) (AR
pers. observ.). The presence of floral bracts is therefore perhaps best regarded as a secondary diagnostic in Nepenthes
except where extensive field observations support the inferences made from pressed materials.
The Nepenthes mollis on Mt. Murud represent the most visited and most extensive populations of this species
currently known, and occur along much of the >6.5 km (2000–2400 m elevation) ridge used as the main approach to
the mountain summit, also a site of biannual religious pilgrimage. The greatest range of diversity in form and colour is
recorded here, no doubt partly because of the number of visits made to the habitat, but also because the plants occur in
a range of situations from dense forest to exposed expanses of rock. This diversity is especially apparent in the neck of
the peristome, which in some plants can become extremely exaggerated, more so than at other known sites. Whether
or not the species evolved here is a matter of conjecture, but the mountain is certainly one of its major strongholds.
Additional specimens examined:—BRUNEI: Cantley s.n. (K! [3 sheets]), Gunong Pagon Priok, 5700 ft [=1737
m], 20 October 1984 [separate lower pitchers; lower pitcher with leaf, rosette with lower pitcher; lower pitcher with
leaf fragment]. SABAH: Hurrell s.n. (K!), S. Sabah, Gunung Luma[r]ku, 1700 m, 8 June 1995 [stem with intermediate
pitcher; annotated Nepenthes “hurrellii”; labelled as paratype of N. hurrelliana but not cited in protologue].
Notes on specimens examined:—The isotype of N. hurrelliana at K was not located by MG during a visit in July
2018 and may have been misplaced.
TABLE 3. A table listing the key differences between Nepenthes mollis and N. sp. Bagong.
Nepenthes mollis Nepenthes sp. Bagong
Stem characteristics Stems stiff, 5–9 mm dia., straight between nodes Stems slender, somewhat lax, 3–5 mm dia.,
fractiflex between nodes
Axillary buds Nodular or slightly filiform Usually activated, forming obvious bract-like
prophylls 0.8–3.5 cm long
Leaf base decurrency Decurrent 2–5 cm (ca. 1/3 to 1/4 of internode,
proportion decreasing with increasing internode length)
Decurrent for entire internode
Inflorescences Emergent from axils, opposed to leaves Emergent from middle of internode, appearing
adnate to stem
Laminae Longitudinal veins inconspicuous, indumentum dense on
both surfaces, persistent
Paired longitudinal veins conspicuous along
outer edges of laminae, indumentum dense,
caducous on adaxial surface
...continued on the next page

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124 • Phytotaxa 392 (2) © 2019 Magnolia Press
TABLE 3. (Continued)
Nepenthes mollis Nepenthes sp. Bagong
Lower pitchers Ventral wings well developed Wings reduced to ridges, otherwise vestigial
towards peristome
Upper pitchers Dense exterior indumentum of scattered short brown
hairs throughout
Indumentum sparser, particularly in upper half
Upper pitcher lid Triangular-ovate with a cordate base, midline rib
prominent with large glandular keel and a 2–3 mm
apical appendage with large pitted glands
Narrowly elliptic and revolute, midline rib
prominent but basal appendage reduced to a
slight swelling
Peristome Broad, generally 3.5 (upper pitchers) to 5 (lower
pitchers) times wider at column than at front of pitcher;
teeth large, 2–3 mm long
2 (upper pitchers) to 3.5 (lower pitchers) times
wider at column than at front of pitcher; teeth
fine, to 1 mm long
Acknowledgements
We thank the Dayak Punan Aqut people who approved the aims our expedition in their traditional lands and provided us
with critical logistical support, particularly Jingom (village chief and guardian of tribal customs), Amat, Bujang, Ferri,
Kueng and Tanyang from Long Sule, Lalung (village chief), Alai, Beni, Bit, Jalung, Lie, Mardison, Nopel, Nuging,
Sem, Sinda, Sion and Udau from Long Pipa, as well as Herman, Ibu Aweq and all elders of the Long Sule–Long Pipa
community for supporting our research; the Mission Aviation Fellowship Kalimantan, particularly Ben Eadie, Craig
Hollander and Tyler Schmidt for air transport assistance; the Geological Society of Malaysia for supplying a geological
map of the island of Borneo; Restorasi Habitat Orangutan Indonesia (RHOI) for accommodating AR, DG, NM, BQ
and our drivers during our overland journey; Richard van Alphen and Ingeborg Eggink at Tropenmuseum, Netherlands,
for assisting MG in locating the original Endert expedition materials and Karien Lahaise at Naturalis, Netherlands,
for help studying said materials; Hannah Clarke, Jim McGregor and Mark Paterson (ABD), Deby Arifiani, Michael
Mambrasar and Atik Retnowati (BO), Martin Cheek (K), Roxali Bijmoer and Nicolien Sol (L), and Noorhana bt Mohd
Sapawi (SAR) for facilitating access to herbarium and type materials; and Richard Nunn, W. Tjiasmanto and John
Yates for generously donating to SM funding essential to the success of the expedition.
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