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Phytotaxa 440 (3): 239–244
https://www.mapress.com/j/pt/
Copyright © 2020 Magnolia Press Article PHYTOTAXA
ISSN 1179-3155 (print edition)
ISSN 1179-3163 (online edition)
Accepted by Pedro Jimenez-Mejias: 8 Apr. 2020; published: 28 Apr. 2020
https://doi.org/10.11646/phytotaxa.440.3.6
239
Schoenus inconspicuus (Cyperaceae, tribe Schoeneae): a new species from
Southern Africa
TAMMY LYNN ELLIOTT1,2,5*, DOUG I. W. EUSTON-BROWN3,6 & A. MUTHAMA MUASYA1,4,7
1Bolus Herbarium, Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch, 7701 Cape Town, South
Africa.
2Institut de recherche en biologie végétale, Département de sciences biologiques, Université de Montréal, 4101 Sherbrooke East,
Montréal, Quebec, H1X 2B2, Canada.
3 Independent researcher.
4 Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AE, UK.
5
�
tammy.elliott@mail.mcgill.ca; https://orcid.org/0000-0003-2162-8537
6
�
dougeb@netactive.co.za; https://orcid.org/0000-0001-6846-2269
7
�
muthama.muasya@uct.ac.za; https://orcid.org/0000-0002-0763-0780
*Author for correspondence.
Abstract
Schoenus is a predominately austral genus of sedges in which the Southern African taxa have recently received detailed
taxonomic attention, starting with a transfer of 24 species into Schoenus from Tetraria and Epischoenus in 2017. The
taxonomy of the Southern African Schoenus species is currently being revised, which has brought insight into the existence
of several species new to science. Here, we build on this recent taxonomic work by describing one new species that has been
previously overlooked (Schoenus inconspicuus), while including a distribution map, an assessment of conservation status
and an updated identification key.
Keywords: Monocots, new species, nomenclature, Schoenus inconspicuus, sedge, species delimitations
Introduction
Schoenus L. (1753: 42) is a genus of perennial graminoids in tribe Schoeneae s.s. (e.g. Viljoen et al. 2013, Larridon
et al. 2018) of the Cyperaceae family, which has its greatest species richness in the southern hemisphere. The highest
number of Schoenus species is in Australasia with 95 accepted species (Musili et al. 2016; WCSP 2020), but as a result
of recent taxonomic work, there is a growing number of Schoenus species recognized in Southern Africa. In 2017, a
taxonomic realignment transferred 24 species of Southern African Tetraria Beauv. (1816: 53–54) and Epischoenus
C.B.Clarke (1894: 657) into Schoenus (see Elliott & Muasya 2017), which was followed by three taxonomic revisions
(Elliott & Muasya 2018; Elliott et al. 2019; Elliott & Muasya 2020) that included the description of 13 new Schoenus
species. In a separate work, Elliott & Muasya (2019) described three other new Southern African Schoenus species and
raised a fourth to the level of species from its previous classification of a variety.
Based on insights from field collections and a review of specimens in the Bolus Herbarium at the University of
Cape Town (herbarium acronym – BOL), the Marie-Victorin Herbarium at the Université of Montréal (herbarium
acronym – MT) and the South African National Biodiversity Institute (herbarium acronyms – NBG and SAM), we
describe here one new species to science: Schoenus inconspicuus T.L.Elliott, Euston-Brown & Muasya. Two specimens
of S. inconspicuus were previously flagged by Elliott & Muasya (2020) as a possible re-occurring allopolyploid,
mutant or a new species (Levyns 6729 and Elliott TE2016_370). In light of our new collections and additional field
observations (see below), we believe that there is enough information to describe S. inconspicuus as a new species.
Schoenus inconspicuus fits morphologically within the Schoenus cuspidatus Rottb. (1773: 66) and allies group, and
is most similar in form to Schoenus ligulatus (Boeckeler) Kuntze (1891: 756). However, key differences in spikelet
morphology and habitat preferences differentiate the two species.
ELLIOTT ET AL.
240 • Phytotaxa 440 (3) © 2020 Magnolia Press
Schoenus inconspicuus T.L.Elliott, Euston-Brown & Muasya, sp. nov (Figs. 1, 2, and 3).
Long, linear-lanceolate spikelets. Glumes relatively long and chartaceous, often shredding with age.
Type:—SOUTH AFRICA. Western Cape: Lower Tokai Park, near N. end, S 34°3’10’’ E 18°26’4’’, 14 m, 17 November 2019, Elliott &
Euston-Brown TE2016_439A (holotype BOL!; isotype MT!).
Note: Variation in the wild might be wider that what is described here, as measurements were made from two specimens. These specimens
were the only ones with the pertinent characters, such as mature spikelets, in a measurable state.
Caespitose, phyllopodic perennial graminoid. Culms terete, 265–506( ‒555) × 0.7–1.0 mm. Leaves basal, 1–3, (69–
)89–160 × 0.3‒0.6 mm, about half the length of the culm or less, usually partially curled, proximally channelled, margin
serrate above sheath. Sheaths firm, reddish-brown, longitudinally striate. Ligule varying from short and firm to longer
and chartaceous, 0.5‒1.4( ‒2.4) mm long. Inflorescence a long, narrow pseudolateral panicle, (45–)51‒96( ‒100) × 4‒6
mm, proximal rachis 17‒37 mm long. Proximal primary inflorescence bracts apex acute to acuminate, not widened at
base, 57‒69 mm long, exceeding length of inflorescence, longitudinal veins not notable, readily breaking-off. Proximal
and subproximal primary inflorescence bracts without membranaceous extensions at base. Spikes 3, (12.0–)16.0‒33.8(
‒43.0) mm long, dispersed along rachis. Spikelets linear-lanceolate, relatively long, 6.6‒8.2 × 1.0‒1.4 mm, pedicellate,
3–6 spikelets per spike. Proximal spikelet prophyll 1 per spikelet, with vein extending to mucro, (0.8–)1.4‒2.4( ‒4.6)
mm long, prophyll mucro (0–)0.6‒1.6( ‒4.2) mm long. Rachilla varying in length, (1.6–)3.8‒6.0( ‒11.6) mm long.
Glumes 4‒6 per spikelet, proximal glume (1.6–)2.4‒5.8( ‒9.1) mm long, subproximal glume 4.2‒6.6( ‒7.8) mm long,
upper glumes longer than basal ones, lower glumes usually over half the length of spikelet, often shredding with time,
usually charteacous in texture. Glume mucros sometimes absent, proximal glume mucro (0–)0.1‒0.3( ‒1.7) mm long,
subproximal glume mucro 0.1‒1.2( ‒2.9) mm long. Stamens 3 per floret, anthers not measured. Stigmas 3-branched
(1 observed), vestigial stigmas of second bisexual floret not observed. Perianth bristles not observed. Nutlet narrow
elliptic, trigonous, yellowish in colour, 2.2‒3.9( ‒4.6) × 0.8‒1.0 mm. Nutlet beak 0.6 mm long (one measured), hispid.
(Figs. 1 and 2).
Distribution and ecology:—Schoenus inconspicuus has been collected from acid sand flats (a rare habitat in
South Africa) between 14 and 250 m in elevation on the Cape Peninsula and western Agulhas Plain region of South
Africa (Fig. 3). This species appears to be rare and localized, having first been collected in 1919 on Bergvliet Farm by
William Purcell (Purcell 592)—an area that has since become a residential suburb. The Levyns’ collection in 1938 on
Rooihoogte is within the Cape of Good Hope National Park, a site where the habitat has been conserved. However,
several recent searches for this population have been unsuccessful. Recently discovered populations in Tokai and the
Agulhas Plain are limited to a few individuals; thus, the currently known total population size of S. inconspicuus is less
than 10 individuals in two small areas.
Phenology—Flowering May and November (one specimen observed for each month), fruiting June (one specimen
observed).
Etymology—The specific epithet “inconspicuus” refers to the fact that this species is not easily noticeable once
it sheds its seeds, and thus it is easily overlooked.
Taxonomic note:—The relatively long, linear-lanceolate spikelets of S. inconspicuus are most similar to those
of S. ligulatus (see Elliott et al. 2019); however, spikelet length, glume texture and relative length, mucro length and
habitat preferences differ between the two species (Fig. 2). Spikelets in S. inconspicuus are longer (> 6.6 mm), whereas
they are generally less than 5.7 mm in S. ligulatus (Elliott et al. 2019). Compared to the glumes of S. ligulatus, those
of S. inconspicuus are more chartaceous in texture appearing silvery-white when young in some specimens. These
‘papery’ glumes then shred as they deteriorate with age. In addition, the lower glumes of S. inconspicuus are relatively
long and often over half to three quarters of the spikelet length, differing from those of S. ligulatus, which are usually
less than half of the length of the spikelet. The glume mucros also differ between the two species, with S. ligulatus
having more prominent aristate lower glumes, whereas the glume mucros of S. inconspicuus are often poorly formed or
lacking. Habitat preference, however, is the most important difference between the two species, with S. inconspicuus
often growing on dry, acid sand, whereas S. ligulatus mostly occurs on wet sites (Elliott et al. 2019).
In its vegetative form, S. inconspicuus seems superficially similar to the grass (family: Poaceae) Tenaxia stricta
(Schrad.) N.P.Barker & H.P.Linder (2010: 352), which can be a common co-occurring species. A rounded tussock
growth form with a tendency to droop and narrow needle-like leaves are shared characters between the two species,
especially when plants are not flowering or without old heads. The difference between the two species only becomes
obvious after carefully inspecting the base of the plant and in the characteristic leaf sheath feature (closed in Schoenus;
A NEW SPECIES OF SCHOENUS INCONSPICUUS Phytotaxa 440 (3) © 2020 Magnolia Press • 241
open in Tenaxia). Another slight difference between the two species is that Tenaxia stricta seems to be lighter green in
colour, while S. inconspicuus tends to be darker green but fades to darker brown with age.
FIGURE 1. Plant growth form, inflorescence and spikelet morphology of S. inconspicuus. A.—general growth form; B.—pressed
specimen; C.—inflorescence; and D.—spikelet. The black scale bar beside the inflorescences in C. represents 10 mm, while the scale bar
beside the spikelet in D. represents 1 mm. The photos in A. and B. were taken with a Sony RX100 II camera, whereas the image in C. was
taken with a Nikon D90 camera attached to a Nikon AF micro Nikkor 105 mm 1:2:8 macro lens. A Nikon DS-US camera head attached to
a Nikon Stereoscopic zoom microscope SMZ1500 was used to take the image in D.
ELLIOTT ET AL.
242 • Phytotaxa 440 (3) © 2020 Magnolia Press
FIGURE 2. Spikelet of S. inconspicuus (A.) compared that of S. ligulatus (B.). The photos were taken with a Nikon DS-US camera head
attached to a Nikon Stereoscopic zoom microscope SMZ1500, and the black scale bar represents 1 mm.
Apart from specimens collected within the last eight years, only two other specimens of S. inconspicuus have
been found in existing herbarium collections: Purcell 592 and Levyns 6729. These two specimens were found during
extensive searches of the BOL, NBG and SAM Cyperaceae collections, with Purcell 592 originally identified as
Tetraria cuspidata (Rottb.) C.B.Clarke (in Durand & Schinz (1894): 660) and Levyns 6729 identified as Tetraria
variabilis Levyns (1947: 87)—two Tetraria species that have since been transferred into Schoenus (Elliott & Muasya
2017). The long, shiny spikelets of both these specimens distinguished them from other Southern African Schoenus
specimens.
Conservation status:—We evaluate the conservation status of Schoenus inconspicuus as CRITICALLY
ENDANGERED (CR) B2ab(ii,iii,iv), C2ai and D under the IUCN Red List categories and criteria (IUCN 2001)
because of its few known populations, small extent of occurrence and the degradation of the habitats surrounding
known populations.
Additional specimens examined:—SOUTH AFRICA. Western Cape: Bergvliet Farm, Constantia, small Gethyllis
camp, 3418 AB, 14 May 1919, Purcell 592 (SAM!); Lower Tokai Park, near N. end, 3418 AB, 14 m, 17 November
2019, Elliott & Euston-Brown TE2016_438 (BOL!); Rooihoogte, 3418 AD, 800′, 12 June 1938, Levyns 6729 (BOL!);
A NEW SPECIES OF SCHOENUS INCONSPICUUS Phytotaxa 440 (3) © 2020 Magnolia Press • 243
Groot Hagelkraal, 3419 AD, 54 m, 8 March 2012, Muasya & Chimphango 6479 (MT!); Groot Hagelkraal farm,
growing about 5 m from side of vehicle trail, 3419 AD, 58 m, 24 August 2018, Elliott & Muasya TE2016_370 (BOL!);
Groot Hagelkraal, within 5 m from vehicle track near limestone cliffs, 3419 AD, 41 m, 20 November 2019, Elliott &
Arens TE2016_474 (BOL!).
Schoenus inconspicuus can be differentiated from similar species in the S. cuspidatus and allies group with linear-
lanceolate spikelets as follows (for more details, refer to Elliott et al. 2019, Elliott & Muasya 2020):
1 Culms less than 340 mm in height; spikelets mostly less than 4.5 mm in length ...................................................... Schoenus exilis
- Culms usually greater than 350 mm in height; spikelets 4.5‒8.2 mm in length ................................................................................2
2 Plants mostly occurring on wet sites; spikelets shorter (generally <5.7 mm) and having relatively short, aristate proximal glumes
(< 2.3 mm); glumes relatively tough (i.e. not completely chartaceous in texture) ...............................................Schoenus ligulatus
- Plants occurring on dry, acidic sands; spikelets relatively long (> 6.6 mm) and having relatively long proximal glumes (mostly >2.4
mm); glumes chartaceous in texture ..............................................................................................................Schoenus inconspicuus
FIGURE 3. Documented collection locations of S. inconspicuus. The map was plotted using R 3.5.1 (R Core Development Team 2013).
Acknowledgements
We are thankful for the support of the Foundational Biodiversity Information Programme (FBIP) of the South African
National Research Foundation (NFR) for grant 104879 to fund herbaria visits and field research. In addition, Tammy
Elliott is grateful of the Smuts Memorial Botanical Fellowship at the University of Cape Town for providing funding
for this project. We would also like to thank the curators at the Bolus Herbarium (BOL) and the South African National
Biodiversity Institute (NBG, SAM) and for allowing access to herbarium specimens. Furthermore, we would like
to thank Leslie Powrie and Jack Viljoen for their help in preparing maps, as well as to Kunz and Elaine Dunn for
providing access to their land. Finally, we thank two anonymous reviewers for their constructive comments. Collection
of new specimens was conducted under CapeNature permit numbers 0028-AAA008-00233 and CN35-28-4102.
ELLIOTT ET AL.
244 • Phytotaxa 440 (3) © 2020 Magnolia Press
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