Schoenus filiculmis T.L.Elliott & Muasya, 2018

Elliott, T. L. & Muasya, A. M., 2018, A taxonomic revision of Schoenus compar - Schoenus pictus and allies (Cyperaceae, tribe Schoeneae) with three new species described from South Africa *, South African Journal of Botany 114, pp. 303-315 : 313-315

7. Schoenus filiculmis T.L.Elliott & Muasya , sp. nov.

Type: South Africa, Western Cape Province, Wuppertal (3219): Swartruggens, Knolfontein , 60 km NE of Ceres, (− DC), 6 Oct 2016, Jardine 2603 (BOL!, holo.; MT!, NBG!, iso.).

Caespitose, phyllopodic perennial graminoid. Short with wiry leaves. Not viscous. Culms terete, (78–)150–193(− 261) × 0.2–0.5(− 0.8) mm. Leaves basal, 2–4(− 5), short and narrow, rarely reaching half the height of the culm, (6.0–)16.0–35.5(− 55.0) × 0.16–0.33(− 2.4) mm, sometimes awl-shaped but most often straight, proximally channelled or not, apex usually flat distally, margin mostly serrate above sheath. Sheaths expanded at base, firm, glossy, often striate, ranging from dark red to reddish-brown in colour proximally. Ligule short, firm or membranaceous, colour ranging from dark-red to whitish, 2-lobed, 0.2–0.7(− 1.4) mm. In fl orescence a short, delicate, narrowly-contracted panicle, 9.5–18.6(− 28.5) × 1.0–3.5(− 4.5) mm, proximal rachis length 4.0–7.0(− 9.5) mm. Proximal primary in fl orescence bracts firm or delicate, often with membranaceous extensions on margins of various widths, 10.0–31.0(− 35.0) mm long, exceeding length of inflorescence or not. Spikes 1–3, 4.0–11.2(− 18.0) mm long, almost completely hidden by membranaceous extensions of inflorescence bracts or not. Spikelets linear-lanceolate, sometimes slightly twisted, ranging in colour from reddish-black to brown, 3.2–5.2(− 5.9) × 0.7–1.3 mm, pedicellate, 1–3(− 4) spikelets/spike. Rachilla (0.2–)1.1–2.4(− 4.2) mm long. Glumes 3–5(− 6) per spikelet, proximal glume (2.2–)2.6–3.0(− 3.4) mm long, subproximal glume (2.6–)3.4–3.8(− 4.9) mm long, firm, shiny, margins sometimes with a narrow scarious margin, obscurely distichous, upper glumes longer in length, apices acuminate to obtuse. Mucros present or not, proximal mucro (0–)0.1–0.3(− 1.1) mm long, subproximal mucro 0–0.2(− 2.1) mm long. Stamens 3 per floret, anthers 2.6–4.0(− 4.5) mm long. Stigmas (2–)3-branched. Perianth bristles 0. Nutlet (only one immature observed) 3-sided, wide elliptical. Nutlet beak farinose ( Figs. 1 and 2 ).

Flowering: May (only one specimen observed)

Distribution and ecology: Schoenus fi liculmis is a species that grows in the western mountains of the Western Cape and Northern Cape provinces of South Africa ( Fig. 9 ). This species generally grows among wet to arid fynbos vegetation on relatively high elevation mountain slopes ranging from approximately 705–1525 m.

Diagnosis: Schoenus fi liculmis is a short species (<275 mm) with a somewhat wiry appearance compared to other similar species because of its narrow culms (<0.8 mm) and leaves, which are usually less than 0.5 mm in width. The leaf sheaths and inflorescences can be dark red to almost black in some specimens. In addition, the inflorescences of S. fi liculmis are generally shorter (<28.5 mm) and narrower (<4.6 mm) compared to other species in the group, appearing delicate in most specimens. Furthermore, the spikelets of this species sometimes have a slight twist so that they appear to curve outwards from the panicle. The inflorescence bracts of S. fi liculmis are relatively short (<45.0 mm) and usually have membranaceous marginal extensions similar to S.aureus , S. pseudoloreus and S. megacarpus ; however, the delicate and wiry habit of S. fi liculmis make it a distinctive species.

Additional collections examined

South Africa. NORTHERN CAPE: 3018 (Kamiesberg): Upper east slopes of Stalberg, Welkom 523, (–AC), 22 Oct 2009, Helme 6116 (NBG). 3119 (Calvinia): Lokenburg, 21 miles S of Niewoudville, (–CA), 14 Oct 1953, Story 4374 (PRE), Story 4375 (GRA, K); Keurfontein 946, Bokkeveld Escarpment, 2 km west of Blomfontein, (–CA), 24 Apr 2009, Helme 6050 (NBG); Lokenburg, (–CA), 27 Sept 1953, Acocks 17,281 (BM, K, PRE). WESTERN CAPE: 3218 (Clanwilliam): Cederberg, Driehoek, (–BB), 18 Sep 2004, Verboom 764 (BOL). 3319 (Worcester): Gydo Mountains, 25–30 km east of Ceres, (–AB), Oct 1975, Arnold 947 (K), Swartruggens; 9 miles N.N.E. of Hoop & Uitkomst, (–BA), 16 Sep 1965, Acocks 23,741 (K, PRE).

Figures

Fig. 1. Examples of plants from each of the seven known species of S.compar - S.pictus group found in southern Africa, showing the corresponding inflorescences and spikelets beneath each plant:A,H and O—S.compar; B,I and P—S.arenicolus, C,J and Q—S.pictus; D,K,and R—S.pseudoloreus; E,L and S—S.aureus; F,M and T—S.megacarpus; and G,N and U—S.filiculmis. The black scale bar beside the inflorescences and spikelets in H—N represents 10 mm, whereas the scale bar beneath O—U represents 1 mm.

Fig. 2. Examples of nutlets from six species of the S. compar - S. pictus group found in southern Africa: A—S. compar; B—S. arenicolus; C—S. pictus; D—S. pseudoloreus; E—S.aureus (immature); and F—S. megacarpus. The black scale bar represents 1 mm.The mature fruit of S.filiculmis is unknown.

Fig. 9. Documented locations of Schoenus filiculmis.