Schoenus purpurascens T.L.Elliott & Muasya, 2019

Elliott, T. L., Barrett, R. L. & Muasya, A. M., 2019, A taxonomic revision of Schoenus cuspidatus and allies (Cyperaceae, tribe Schoeneae) - Part 1 *, South African Journal of Botany 121, pp. 519-535 : 533

10. Schoenus purpurascens T.L.Elliott & Muasya , sp.nov. Type: South Africa, Western Cape Province, 3419 (Caledon): Nidderdale Farm, S.E.- facing slope to N.E. of Babylon's Tower peak, near top of peak, (–AD), 5 May 2018, Elliott, Muasya and van Mazijk TE2016_349 ( BOL!, holo., MT!, NBG!, iso.).

Caespitose, phyllopodic perennial graminoid. Culms terete, slender, (193–)339–528(—732) × 0.4–0.9 mm. Leaves basal, 2–4(—8), (4–) 54–149(—392) × 0.2–1.4 mm, mostly straight, usually not proximally channelled, margin usually serrate above sheath. Sheaths membranaceous with reddish-purple streaks, usually loosely clasping culm, longitudinally striate. Ligule membranaceous, varying lengths, 0.3–1.1(—9.2) mm long. In fl orescence a pseudolateral panicle, 9–33(— 45) × 3–12 mm, proximal rachis length 4–16(—29) mm. Proximal primary in fl orescence bracts slender, not channelled, apex acute to acuminate, never widened at base, 29–66(—206) mm long, exceeding length of inflorescence up to several times, without notable longitudinal veins. Proximal and subproximal primary inflorescence bracts never with membranaceous extensions at base. Spikes 2–11, (4.0–) 7.4–19.0 mm long, usually dispersed along rachis. Spikelets ovate, 2.6–4.1 × 1.0– 1.7 mm, pedicellate, 2–10 spikelets per spike, reddish-brown sometimes with narrow hyaline margins. Proximal spikelet prophyll 1 per spikelet, with a raised vein extending to mucro, 0.4–1.1 mm long, prophyll mucro 0.8–2.5(—3.6) mm long. Rachilla 0.8–2.8 mm long. Glumes 4–7 per spikelet, proximal glume 0.4–1.8 mm long, subproximal glume 0.6–2.2 mm long, upper glumes longer than basal ones, apex acute to acuminate. Glume mucros relatively short, proximal mucro 0.1–0.8 mm long, subproximal mucro 0.1–0.3 mm long. Stamens (1–)3(—5) per floret, anthers 1.3–3.7 mm long. Stigmas 3-branched, vestigial stigmas of second bisexual floret sometimes present. Perianth bristles not observed. Nutlet not present on examined specimens ( Figs. 2 and 4 ).

Flowering: November to May

Distribution and ecology: Schoenus purpurascens is a relatively narrow-ranged species of mountainous regions of the southwestern part of the Western Cape Provinces of South Africa, with its distribution centred mostly around the Caledon region ( Fig. 19 ). This species can be found growing on mountain slopes ranging from 275 to over 1000 m, with moisture regimes varying from moist to well-drained.

Diagnosis: Schoenus purpurascens is a species with loose membranaceous leaf sheaths (often with small reddish-purple streaks), non-channelled basal leaf blades (leading to the leaves appearing flat), as well as ovate spikelets (<4.1 mm long) with relatively short mucros. Schoenus bolusii also has membranaceous leaf sheaths with reddish-purple streaks ( Fig. 13A ); however, the leaf blades of the two species differ, as those of S. purpurascens are most often not channelled and thus appear flat compared to the channelled, terete leaf blades of S. bolusii . In addition, S. purpurascens has ovate spikelets ( Fig. 4P ), whereas those of S. bolusii are between lanceolate to ovate in shape. Schoenus calceolus and S. prophyllus also have ovate spikelets; however, those two species do not have the non-channelled leaves of S. purpurascens .

Additional collections examined

South Africa. WESTERN CAPE: 3418 (Simonstown): River Zondereinde Mts. , (–BD), Apr 1930, Stokoe 2163 ( BOL) ; Oudebos, RiverZonderEnd Mts., (–BD), May 1930, Stokoe 2100 c ( NBG) ; Riviersonderend Mtns., (–BD), Apr or May 1950, Stokoe 68,118 ( NBG) ; Kogelberg Forest Reserve, N.E. side of Pringle Peak along path, (–BD), 12 May 1969, Boucher 304 ( NBG) ; Kogelberg Forest Reserve , Paardeberg, 30̊ side of kloof facing S.W. on summit of Paardeberg, (–BD), 25 Feb 1970, Boucher 1155 ( NBG) . 3419 (Caledon): Grabouw Forest Reserve , Valleiberg, E. slope, (–AA), 20 May 1969, Stehle 96 ( NBG) ; Lebanon State Forest , Jakkalsrivier Catchment Id., (–AA), 12 Apr 1972, Haynes 615 ( NBG) ; Lebanon State Forest , Jakkalsrivier Catchment Ib., (–AA), 26 Mar 1973, Haynes 785 ( NBG [2 sheets]) ; mountains above Kleinmond, (–AC), 1 Apr 1934, Stokoe 2694 ( BOL) ; Babylon's Tower, on steep peaty S. slopes of ridge and also among rocks on upper slopes, (–AC), 16 Nov 1969, Esterhuysen 32,322 ( BOL, K) ; Schilpadkop area, above Happy Valley , R.Z.E. Mts., (–AD), 30 Nov 1952, Esterhuysen 20,795 ( BOL, K), Esterhuysen 20,796 ( BOL, K) ; Schilpadkop, R.Z.E. Mts., near Greyton, marshy S. slope, above Happy Valley , (–AD), 2 Jan 1953, Esterhuysen 21,038 ( BOL, K) ; Hermanus, Fernkloof Nature Reserve , (–AD), 5 Mar 1974, Orchard 65 (K, NBG) ; Rivier Zonder Einde Mts. , near ZonderEnd, (–BA), 16 Jun 1949, Wilman 505 ( BOL) ; Kleinmond, (–BD), Apr 1930, Stokoe s.n. ( SAM) ; Kogelberg, Harold Porter N.R., Leopards Kloof, W. of waterfall, (–BD), 4 Aug 2017, Helme 9207 ( BOL, MT, NBG) .

Figures

Fig.2. Examples of nutlets from 11 species of the Schoenus cuspidatus and allies group found in southern Africa:A—S.auritus; B—S.graminifolius; C—S.ligulatus; D—S.exilis; E—S.bolusii; F— S.submarginalis; G—S.crassiculmis; H—S.quartziticus; I—S.limosus; J—S.purpurascens; and K—S.calceolus (immature).The black scale bar represents 1 mm.The mature fruits of S.calceolus and S.prophyllus are unknown.

Fig.4. Examples of plants from six species of the Schoenus cuspidatus andallies group found in southern Africa,showing the corresponding inflorescences and spikelets beneath each plant: A,G and M—S.crassiculmis; B,H and N—S.quartziticus, C,I andO—S.limosus; D,J,and P—S.purpurascens; E,K andQ—S.prophyllus; and F,L and R—S.calceolus. The black scale bar adjacent to the inflorescences in G—L represents 10 mm, while the scale bars adjacent to the spikelets in M—R represent 1 mm.

Fig. 19. Documented locations of Schoenus purpurascens.

Fig. 13. Upper sheath and ligule of Schoenus bolusii (A) and S.submarginalis (B).The black scale bar represents 1 mm.