Dilochia deleoniae (Orchidaceae), a new species from Mindanao, Philippines

Abstract

A new species, Dilochia deleoniae Tandang & Galindon (Orchidaceae), from Mindanao Island, Philippines is described and illustrated herein. This species is distinct from other known Philippine Dilochia species by its terrestrial habit and is distinguished from all known Dilochia species by its monopodial inflorescence, rarely branching in two, and a pale yellow to dull orange or brownish-yellow labellum devoid of purple spots.

Full text

New species of orchid from the Philippines 91
Dilochia deleoniae (Orchidaceae),
a new species from Mindanao, Philippines
Danilo N. Tandang1, John Michael M. Galindon1, Edwin R. Tadiosa1,
Fulgent P. Coritico2, Victor B. Amoroso2, Noel E. Lagunday2,
Rene Alfred Anton Bustamante3, Darin S. Penneys4, Peter W. Fritsch5
1 Botany and National Herbarium Division, National Museum of the Philippines, Padre Burgos Drive, 1000
Ermita, Manila, Philippines 2 Center for Biodiversity Research and Extension in Mindanao (CEBREM),
Central Mindanao University, Musuan, Bukidnon, Philippines 3 Philippine Taxonomic Initiative, El Nido,
Palawan, Philippines 4 University of North Carolina-Wilmington, Wilmington, NC 28403, USA 5 Botanical
Research Institute of Texas, 1700 University Drive, Fort Worth, Texas 76107-3400, USA
Corresponding author: John Michael M. Galindon (jm_galindon@yahoo.com)
Academic editor: V. Droissart|Received 29 September 2019|Accepted 30 November 2019|Published 4 February2020
Citation: Tandang DN, Galindon JMM, Tadiosa ER, Coritico FP, Amoroso VB, Lagunday NE, Bustamante RAA,
Penneys DS, Fritsch PW (2020) Dilochia deleoniae (Orchidaceae), a new species from Mindanao, Philippines. PhytoKeys
139: 91–97. https://doi.org/10.3897/phytokeys.139.46935
Abstract
A new species, Dilochia deleoniae Tandang & Galindon (Orchidaceae), from Mindanao Island, Philip-
pines is described and illustrated herein. is species is distinct from other known Philippine Dilochia
species by its terrestrial habit and is distinguished from all known Dilochia species by its monopodial in-
orescence, rarely branching in two, and a pale yellow to dull orange or brownish-yellow labellum devoid
of purple spots.
Keywords
biodiversity, Mount Hamiguitan Range Wildlife Sanctuary, orchid taxonomy, world heritage site
Introduction
Dilochia Lindl. is a genus in the Orchidaceae comprising ten species found in South-
east Asia and New Guinea (omas 1993; Sulistriarini 2012; Ormerod 2015; Govaerts
et al. 2019). Only two species have been previously recorded in the Philippines (Pelser
PhytoKeys 139: 91–97 (2020)
doi: 10.3897/phytokeys.139.46935
http://phytokeys.pensoft.net
Copyright Danilo N. Tandang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC
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Danilo N. Tandang et al. / PhytoKeys 139: 91–97 (2020)
92
et al. 2011 onwards), viz. D. elmeri Ames and D. wallichii Lindl., both of which are
epiphytic. D. elmeri is endemic to the Philippines with extant populations in Luzon
(Rizal), Visayas (Samar and Leyte), and Mindanao (Davao), whereas the native range
of D. wallichii encompasses the Malesian region and ailand.
e new species was discovered in 2016 by the rst author during the botanical
survey for the Global Environment Facility (GEF)–funded project, ‘Removing Barri-
ers to Invasive Species Management in Production and Protection Forest in Southeast
Asia (FORIS)’, in the Mount Hamiguitan Range Wildlife Sanctuary (MHRWS). Two
owering individuals of Dilochia were documented and collected inside a sampling
quadrat. Unfortunately, measurements and the description of characters in situ were
not made before the specimens were pressed and dried. Several owering individu-
als were observed and collected during eldwork with Central Mindanao University
(CMU) and the Botanical Research Institute of Texas (BRIT) in June 2019. Further-
more, fruiting specimens were collected in subsequent eldwork conducted by CMU
together with the rst author in August 2019.
Photographs and in situ descriptive observations of the colors of vegetative and
reproductive structures were captured during botanical inventories in 2016 and 2019.
Illustrations and further detailed morphological and microscopic examinations of four
voucher specimens preserved in denatured alcohol were recorded at the Botany and
National Herbarium Division, National Museum of the Philippines. Measurements
of important plant parts were made using Mitutoyo Digimatic Caliper. On detailed
examination, the authors realized that this species diers greatly from all other spe-
cies of Dilochia. erefore, we have described and illustrated the new species Dilochia
deleoniae Tandang & Galindon, the third species from the Philippines and 11th species
in the world.
Taxonomy
Dilochia deleoniae Tandang & Galindon, sp. nov.
urn:lsid:ipni.org:names:77205270-1
Figs 1–2
Diagnosis. is species is distinct from the two known epiphytic Philippine species by
having an entirely terrestrial habit. Further, among the characters that separate it from
other known Dilochia species, the new species has a monopodial inorescence or rarely
branching in two. It is similar to D. beamanii Ormerod (Ormerod 2015) of Sabah, Ma-
laysia in its reproductive structures. Both species have a terminal ower, with similarity
in shape and color of bracts, sepals, and petals. Furthermore, their columns are both
winged and with small variation in length. However, the new species has a monopodial
inorescence or rarely branching in two, bearing 7 to 9 owers (vs. a 3- to 6-branched

New species of orchid from the Philippines 93
Figure 1. Line drawings of Dilochia deleoniae Tandang & Galindon sp. nov. A habit B ower C dorsal
sepal D pair of petals E pair of lateral sepals F side view of the pedicel including the ovary and the column
G front view of the pedicel including the ovary and the column H column I side view of the labellum
J front view of the labellum with attened side lobes. Scale bars: 5 cm (A); 1 cm (B–J). Illustrated by
Rolf Campos.

Danilo N. Tandang et al. / PhytoKeys 139: 91–97 (2020)
94
Figure 2. Dilochia deleoniae Tandang & Galindon sp. nov. A ower details showing the colorations of the
sepals, petals, labellum and bracts B racemose inorescence C semi-pendulous inorescence and the alternate
arrangement of the leaves D dark-purpled fruits E cross section of the fruit showing numerous whitish seeds
F habitat on the summit of Mount Hamiguitan, forest over ultramac soils. Scale bars: 1cm (A, B , D, E );
5cm (C). A, C , F photos by John Michael M. Galindon B, D, E photos by Danilo N. Tandang.

New species of orchid from the Philippines 95
inorescence bearing ≥ 13 owers in D. beamanii); dorsal sepal 11-veined, lateral sepal
10-veined, and petal 8-veined (vs. dorsal sepal 5-veined, lateral sepal 5-veined, and
petal 7-veined in D. beamanii). In addition, the labellum of D. beamanii is yellow-
ochre with white margins and apex, and with purple spots, whereas the new species has
a labellum with a white base and a pale yellow to dull orange or brownish-yellow lip
from the disc to the margins and is consistently devoid of purple spots.
Type. P • Mindanao Island. Davao Oriental: San Isidro Municipality,
Mount Hamiguitan Range Wildlife Sanctuary, 6°43'47.40"N, 126°10'53.90"E, forest
on ultramac soil, 07 July 2016, E.R. Tadiosa 2059 with D.N. Tandang (holotype:
PNH; isotypes: CMUH, BRIT, CAHUP).
Description. Terrestrial clump-forming herb, stem 70.0–182.0 cm × 4.0–
6.3mm (with sheaths), terete, erect, leafy throughout becoming leaess near base.
Leaf sheaths: purple becoming light green near leaf base, tubular, longer at lower half
of stem, 21.4–38.6 mm long, gradually decreasing to last leaf distally. Leaves: light
green abaxially, dark green to purplish adaxially, alternate, spreading, curved down-
ward at distal half, glossy, glabrous, lanceolate, usually larger below stem, 57.1–69.6
× 18.7–23.0mm, smaller ones distally 22.1–23.5 × 9.0–9.7 mm, prominently 7 or
8 parallel veins adaxially; apex attenuate, margin entire, purple to light green. Ino-
rescence: terminal, racemose, semi-pendulous, to 65.0 mm long, 7- to 9-owered;
peduncle light yellow, glabrous, bearing 3 internodes, 23.3–28.4 mm long, enclosed
by 3 sterile acuminate peduncular scales; peduncular scales cymbiform, parallel veins
numerous, vinaceous abaxially, ivory to cream adaxially, apex acute, 16.4–20.4 ×
9.8–14.4 mm wide. Floral bracts: clasping pedicels, glabrous, variable in color from
yellow green to cream with vinaceous coloration outside at margin and apex, cymbi-
form, 14.8–21.3 ×6.5–12.4mm, apex acuminate. Pedicel including ovary: 20.4–
23.1 mm long, terete, glabrous, clavate, pale green with occasional purple markings.
Ovary: dark purple to green, 6-ribbed. Flowers: with creamy white sepals and petals,
eshy, labellum whitish at the base, becoming pale yellow to dull orange or brown-
ish-yellow except white at apex, underside white with yellow margin at epichilium.
Dorsal sepal: cymbiform, lanceolate, 26.9–27.7 × 8.8–9.9 mm, apex obtuse-acute,
nerves 11. Lateral sepals: obliquely lanceolate, 26.9–28.8 × 7.2–9.3 mm, apex con-
duplicate, attenuate, nerves 10. Petals: oblong-oblanceolate, 25.8–26.7 × 8.3–9.5
mm, apex subobtuse, nerves 8. Labellum: oblong-elliptic, 3-lobed, 21.1–21.6 mm
long; carinae 5, longitudinal on lip disc, undulating, inner 3 originating from base
of labellum to tip, 2 outer shorter than 3 middle, originating from middle part of
labellum to middle portion of epichilium; hypochilium elliptic, 12.0–12.9 × 9.5–
10.0 mm, with erect side lobes, margin entire, apex praemorse, 3-keeled over length
of hypochilium, side lobes with numerous parallel veins pointing toward margin;
epichilium oblong-elliptic, 8.1–8.2 × 4.1–4.9 mm, apex rounded, margin crisped;
keels 5, inner 3 continuing from hypochilium, longer than outer 2. Column: slender,
16.2–16.7 × 4.3–5.0 mm, white, light yellow at base, narrow-winged, widened at
the apex. Fruits: ovate, 21.9–27.3 mm long, dark purple to green, tinge of purple at
ridge, ovate, 6-grooved, perianth persistent. Seed: winged, 1.6–2.0 × 0.1–0.2 mm,
white, numerous.

Danilo N. Tandang et al. / PhytoKeys 139: 91–97 (2020)
96
Distribution. Endemic to the Philippines. Mindanao Island, Davao Oriental, San
Isidro Municipality, Mount Hamiguitan Range Wildlife Sanctuary.
Habitat and ecology. is terrestrial orchid species prefers open to partly shaded
habitat, where it is found in clumps or scattered. e populations rarely occur in for-
est over ultramac rocks between elevations ca. 1100–1200 meters above sea level (m
a.s.l.) but is common in the pygmy forest ecosystem at the mountain summit between
1560 and 1650 m a.s.l. is new species was recorded inside a sampling quadrat, grow-
ing with other native orchid species such as Appendicula tembuyukenensis J.J.Wood
and Dendrochilum kopi Lückel., and with other species such as Agathis sp., Dacry-
dium beccarii Parl., Dacrydium elatum (Roxb.) Wall. ex Hook., Falcatifolium gruezoi
de Laub., Gleichenia vulcanica Blume, Leptospermum javanicum Blume, Machaerina
disticha (C.B.Clarke) T.Koyama, M. glomerata (Gaudich.) T.Koyama, Medinilla myr-
tiformis (Naudin) Triana, M. theresae Fernando, Myrsine amorosoana Pipoly, Scaevola
micrantha C.Presl, Symplocos polyandra (Blanco) Brand, Tasmannia piperita (Hook.f.)
Miers, and Vaccinium spp.
Additional specimens examined. P • Mindanao Island, Davao Ori-
ental Province, Municipality of San Isidro, Mount Hamiguitan Range Wildlife Sanc-
tuary; 6°43'49.26"N, 126°10'48.22"E; 1204 m elevation; 18 June 2019; Plants and
Lichens of the Southern Philippines Survey 758 (BRIT, CMUH, PNH) • Mindanao
Island, Davao Oriental Province, Municipality of San Isidro, Mount Hamiguitan
Range Wildlife Sanctuary; 6°43'49.15"N, 126°10'45.41"E, 1184 m elevation, 18
June 2019, Plants and Lichens of the Southern Philippines Survey 1316 (BRIT,
CMUH, PNH).
Etymology. e new species is named after Ms Josena De Leon, the former Chief
of the Wildlife Resources Division under the Biodiversity Management Bureau of the
Department of Environment and Natural Resources, who has pursued wildlife conser-
vation for more than 35 years and who remains a biodiversity conservation advocate.
During her time in the Bureau, the FORIS project was launched and researchers from
the National Museum of the Philippines were invited to be part of the technical work-
ing group that led to the discovery of the new species.
Conservation status. Dilochia deleoniae is only known from the 68.34 km2
Mount Hamiguitan Range Wildlife Sanctuary and is conned to its high elevations
particularly in mossy-pygmy forests. e extent of occurrence is < 100 km2 and area
of occupancy is 8 km2, as based on GeoCAT (Bachman et al. 2011; http://geocat.kew.
org/) with the default 2 km2 grid. e mountain range was declared a protected area
under Republic Act No. 9303, and was recently designated as a UNESCO World
Heritage Site, helping to protect this species from habitat degradation, poaching,
and over-collection. However due to ‘restricted area of occupancy’ and the possible
eect of continuous poaching and climate change, this species is ‘capable of becom-
ing critically endangered or extinct within a very short time’. erefore, following
the IUCN Categories and Criteria (IUCN 2012), we classify this species as Vulner-
able [VU D2].

New species of orchid from the Philippines 97
Acknowledgements
We thank Director-General Jeremy Barns (NMP), Deputy Director-General Ana
Maria eresa P. Labrador (NMP) and Dr Luisito T. Evangelista (Curator of Botany
and National Herbarium Division) for supporting this research; Rolf Campos for the
botanical illustrations; Dr Paul Ormerod and Dr Jim Cootes for their generosity in
providing either hard or soft copies of Dilochia references; the Department of Environ-
ment and Natural Resources (DENR) – Region 11 for the issuance of Gratuitous Per-
mit and transport permits. Support for this research was provided by the GEF through
the United Nations Environmental Fund (UNEF), with the DENR-Biodiversity Man-
agement Bureau (formerly Protected Area and Wildlife Bureau) as the implementing
agency; the Department of Science and Technology – Grant In-Aid (DOST–GIA);
and the U.S. National Science Foundation (DEB-1754697 and DEB-1754667). All
specimens were collected under the permit issued by the National Museum of the
Philippines and Gratuitous Permit XI-2019-21.
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