Schoenus brunnescens T.L.Elliott & Muasya, 2020

Elliott, T. L. & Muasya, A. M., 2020, A taxonomic revision of Schoenus cuspidatus and allies (Cyperaceae, tribe Schoeneae) - Part 2, South African Journal of Botany 130, pp. 327-347 : 330-332

1. Schoenus brunnescens T.L.Elliott & Muasya , sp. nov.

Type: South Africa, Western Cape Province, 3321 (Ladismith): N. side of Garcia's Pass, along R323, within 2 km to N. of pass summit along road to Ladismith, past turnoff to Langkloof , (‒CC), 8 Jul 2017, Elliott, Muasya & Muthaphuli TE2016_221 ( BOL!, holo.; MT!, iso.).

Caespitose, phyllopodic perennial graminoid, sheaths often brown coloured ( Fig. 3A ). Culms terete, (240 —)303 — 564(— 687) X (0.5 —) 0.7 — 1.0 mm. Leaves basal, ranging from less than half to nearly the full height of the culms, 2 — 4, 13 — 192(‒206) X 0.2‒0.7(— 0.9) mm, proximally channelled, margin serrate above sheath, usually straight, firm and rigid. Sheaths usually brown with a tinge of red at base but paler brown above, firm, longitudinally striate. Ligule firm, 0.4 — 1.0(— 2.6) mm long. In fl orescence a pseudolateral panicle, narrow, (19 —)25‒30 (— 35) X (3.0 —)4.5‒5.1(— 7.5) mm, proximal rachis length 7‒14(— 18) mm ( Fig. 3F ). Proximal primary in fl orescence bracts firm, apex acuminate, channelled, narrow at base, (40 —) 61‒102 mm long, exceeding length of inflorescence up to several times. Spikes 6‒13, 4‒7(— 10) mm long, aggregated into thin clusters along rachis, slightly overlapping. Spikelets lanceolate, 2.7‒4.0 X 0.5‒1.1 mm, pedicellate, 3 — 7 spikelets per spike, usually light reddish-brown in colour ( Fig. 5A ). Proximal spikelet prophyll 1 per spikelet, well-developed, with notable, raised vein extending to mucro, 0.6‒1.2(— 1.7) mm long, mucros varying in length, (0.4 —)1.3‒3.1(— 5.6) mm long. Rachilla (0.2‒)0.6‒1.1(— 1.7) mm long. Glumes 4‒7 per spikelet, often scarious (especially lower glumes), sometimes with hyaline margins, first three glumes usually relatively long (as in S. crassus ), proximal glume (0.6‒)1.1‒1.5(— 2.0) mm long, subproximal glume (0.6‒)1.0‒1.6(— 2.5) mm long, upper glumes longer than basal ones, apex acute to obtuse. Glume mucros often relatively short, proximal mucro (0.2‒)0.5‒1.0(— 1.4) mm long, subproximal mucro (0‒) 0.4‒0.7 mm long. Stamens 2‒3 per floret, anthers 1.0‒ 2.3 mm long. Stigmas 3-branched, vestigial stigmas of second bisexual floret yet to be observed. Perianth bristles absent (i.e. yet to be observed). Nutlet relatively small, spherical (more nutlets require examination), trigonous, yellowish in colour when young, 1.0‒ 1.4 X 0.5‒0.6 mm ( Fig. 6A ). Nutlet beak 0.3‒0.4 mm, hispid.

Flowering: July (two specimens observed)

Distribution and ecology: Schoenus brunnescens is known to occur in the Western Cape Province of South Africa, ranging from the Rooi Els and Worcester areas in the west to the Langeberg Mountains in the east ( Fig. 7 ). This species has a known elevational range of 70‒610 m, and it usually grows on coarse-textured soils in the fynbos vegetation type.

Diagnosis: The brown culm bases of S. brunnescens make it unique amongst most Southern African Schoenus , except Schoenus bracteosus T.L.Elliott & Muasya ; however, it does not have firm primary inflorescence bracts that enclose the spikes as in S. bracteosus (see Elliott and Muasya, 2019). The straight and stiff culms and leaves of S. brunnescens are similar to those of S. compactus and S. crassus ( Fig. 3 ), but those two species generally have darker (i.e. more reddish-brown) culm bases, longer spikelets and larger nutlets compared to this species ( Figs. 5 and 6 ). In addition, S. brunnescens has a thinner, more elongated inflorescence compared to the congested (or compact) panicle of S. compactus ( Fig. 3F and G ).

Additional collections examined

South Africa. WESTERN CAPE: 3318 (Cape Town): Steenbras Dam , (— BB), 8 Mar 1947, Levyns 8705 ( BOL). 3319 (Worcester): Klein Drakenstein Mountains, Upper Zachariashoek Catchment , (— CC), 25 Feb 1971, Kruger 1125 ( NBG). 3321 (Ladismith): N. side of Garcia's Pass, within 1 km of farm, within 5 m of road to Langkloof , (— CC), 8 Jul 2017, Elliott, Muasya & Muthaphuli TE2016_218 ( BOL); Langeberg, Bergfontein, on S.E. footslopes of Koksposberg to E. and immediately above cultivated lands, (— DC), 18 Jan 1991, McDonald 2056 ( NBG, PRE). 3418 (Simonstown): southern Hottentots Holland Mountains, Kogelberg State Forest , ± 0.75 km from 2nd dwelling at Oudebos , left of road at 2nd koppie, (— BD), 11 Mar 1992, Kruger K. 431 ( NBG) . 3419 (Caledon): Houhoek, Houtech terrain, in area of Lookout , near Escom pylon, (— AA), 17 Apr 1988, Boucher & Stindt 5387 ( NBG) ; Howhoek, (— AA), 2 Jul 1896, Schlechter 7403 ( BM, K) ; above Rooi Els, (— BD), 1 Jul 1952, Parker 4755 ( BOL [2 sheets], K [2 sheets], NBG) . 3420 (Bredasdorp): De Hoop Nature Reserve, Potberg Mountain , (— BC), 30 Nov 2017, Elliott & Smith TE2016_322 ( BOL) , Elliott & Smith TE2016_323 ( BOL) .

Figures

Fig. 3. Examples of plants from five species of the S. cuspidatus and allies group found in Southern Africa, showing the corresponding inflorescences beneath each plant: A and F—S. brunnescens; B and G—S.compactus; C and H—S.crassus; D and I—S.loreus; and E and J—S.galpinii. The black scale bar adjacent to the inflorescence in J represents 10 mm.

Fig. 5. Examples of spikelets from nine species of the S. cuspidatus and allies group found in Southern Africa:A—S. brunnescens; B—S. compactus; C—S. crassus; D—S.loreus; E—S. gal- pinii; F—S.cuspidatus; G—S.graciliculmis; H—S.riparius; and I—S.australis. The black scale bar represents 1 mm.

Fig. 6. Examples of nutlets from nine species of the S.cuspidatus and allies group found in Southern Africa:A—S. brunnescens; B—S. compactus; C—S. crassus; D—S. loreus; E—S. galpinii; F—S.cuspidatus; G—S.graciliculmis; H—S.riparius; and I—S.australis. The black scale bar represents 1 mm.

Fig. 7. Documented locations of S. brunnescens.