Schoenus australis 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 : 345

9. Schoenus australis T.L.Elliott & Muasya , sp. nov.

Type: South Africa, Eastern Cape Province, 3424 (Humansdorp): St. Francis Bay area, trails on W. side of St. Francis Links golf course, (‒BB), 9 Nov 2017, Elliott, Betz & Logie TE2016_266 ( BOL!, holo.; MT!, iso.).

Caespitose, phyllopodic perennial graminoid ( Fig. 4D ). Culms often relatively tall, terete, (305 —)425 — 500(— 710) X 0.4 — 0.8(— 1.2) mm. Leaves basal, relatively narrow, usually half the height of culms or more, 1 — 4, (58 —)120 — 363(— 480) X 0.3‒0.5(— 0.7) mm, proximally channelled, margin serrate above sheath, usually straight, firm (but not stiff as in S. crassus ). Sheaths dark reddish-brown at base but paler above, firm, longitudinally striate. Ligule firm, relatively short, 0.3 — 0.7(— 1.0) mm long. In fl orescence a pseudolateral panicle, reddish-brown turning brown with maturity, mucros from prophylls and glumes obvious so that inflorescence appears ‘bearded’, (28 —) 31‒48(— 57) X 4.5‒8.5(— 13.0) mm, proximal rachis length 10‒16 (— 26) mm ( Fig. 4H ). Proximal primary in fl orescence bracts firm, apex acuminate, channelled, narrow at base, (44 —)75‒117(— 163) mm long, exceeding length of inflorescence up to several times. Spikes several aggregated into clusters along rachis, varying in number, 4‒ 17, 4‒10(— 15) mm long, slightly overlapping. Spikelets lanceolate, somewhat aristate, (3.0 —)3.8‒4.5(— 5.3) X 0.6‒1.0(— 1.4) mm, pedicellate, 3 — 7 spikelets per spike, usually light reddish-brown in colour ( Fig. 5I ). Proximal spikelet prophyll 1 per spikelet, well-developed, with notable, raised vein extending to mucro, 0.2‒0.7(— 1.4) mm long, mucros often very long, (1.7 —)3.2‒5.5(— 9.3) mm long. Rachilla (0.2 —)0.7‒1.5(— 2.5) mm long. Glumes 4‒8 per spikelet, first three glumes usually relatively long (as in S. crassus ), proximal glume (0.6‒)1.2‒1.5(— 2.1) mm long, subproximal glume 1.1‒1.8(— 2.2) mm long, sometimes with narrow hyaline margins but often without, upper glumes longer than basal ones, apex acute to obtuse. Glume mucros varying in length, proximal mucro (0.2‒)0.7‒1.4(— 4.7) mm long, subproximal mucro 0.1‒1.1(— 2.0) mm long. Stamens 2‒3 per floret, anthers (1.6‒)2.0‒3.0 mm long. Stigmas 3-branched, vestigial stigmas of second bisexual floret absent (i.e. yet to be observed). Perianth bristles absent (i.e. yet to be observed). Nutlet broad elliptic, trigonous, yellowish in colour when young (older nutlets yet to be observed) 1.8‒2.6(— 2.9) X 0.9‒1.0 mm ( Fig. 6I ). Nutlet beak 1.3 mm (one measured).

Flowering: June to November

Distribution and ecology: Schoenus australis is known to occur along the southern coast of South Africa, from Rooi Els in the Western Cape Province to the Port Elizabeth area in the Eastern Cape Province ( Fig. 16 ). This species has been recorded from elevations ranging from sea level to 600 m, mostly on sand substrates (e.g. dunes). However, it has also been collected from sandstone and limestone fynbos, floodplains, seepage areas and road edges.

Diagnosis: Schoenus australis is a robust species with a relatively long and wide inflorescence that appears ‘bearded’ because of the prominent primary inflorescence bracts, as well as relatively long prophyll and glume mucros ( Fig. 4D and H ). Schoenus loreus also has a relatively long and dense inflorescence ( Fig. 3I ), but it has non-channelled, flat leaves ( Fig. 3D ) compared to the terete leaves of S. australis . Distributions and habitats differentiate S. australis from S. riparius , which is a taller species endemic to wet areas on the Cape Peninsula of South Africa ( Fig. 15 ). Furthermore, the inflorescence of S. riparius is almost always wider and longer than that of S. australis ( Fig. 4G and H ).

Other species that could be mistaken for S. australis include S. crassus and S. cuspidatus , whose distributions overlap. The leaves of S. crassus tend to be shorter (i.e. less than half the culm height) and firmer than those of S. australis , which tends to have longer (often over half the culm height) and more lax basal leaves ( Figs. 3C and 4D ). Schoenus australis has relatively longer, aristate lower glumes that differ from the cuspidate and short lower glumes of S. cuspidatus ( Fig. 5F and I ).

Additional collections examined

South Africa. EASTERN CAPE: 3325 (Port Elizabeth): Humewood, Port Elizabeth , (— DC), 8 Nov 1962, Dahlstrand 149 ( PRE) . 3424 ( Humansdorp ) : Cape St. Francis , (— BB), 23 Mar 1979, Cowling 22 ( GRA) ; road to Op Water, Kromme River , (— BB), 19 Nov 1979, Cowling 1293 ( GRA) ; Thuyspunt (S. of Humansdorp), next to E. Thuyspunt gate, (— BB), 12 Oct 2007, Low, Walton & Logie ABL 15,368 ( GRA) ; St. Francis Bay area, trails on W. side of St. Francis Links golf course, 9 Nov 2017, Elliott, Betz & Logie TE 2016_265 ( BOL) ; outskirts of Cape St. Francis, Irma Booysen Flora Reserve , (— BB), 9 Nov 2017, Elliott & Betz TE 2016_270 ( BOL) . WESTERN CAPE: 3418 (Simonstown): Rooiels river mouth, Hangklip , (— BD), 14 Jul 1981, Parsons 246 ( NBG) ; Betty's Bay, N. shore of Grootwitvlei, off Retzia Road , (— BD), 26 Feb 2004, Joubert 676 ( NBG) . 3419 (Caledon): Elgin Basin, Arieskraal Farm (portion Solva ), on Bokkeveld Shales in horseshoe bend of Palmiet River , (— AA), 2 Apr 1993, Rode & Boucher 77 ( NBG) ; 4 Sep 1993, Rode & Boucher 143 ( NBG) ; Rooi Els , (— BD), 2 Aug 1947, Parker 4221 ( NBG) ; Bettys Bay , (— BD), 6 Dec 1951, Parker 4689 ( NBG) ; near Pringle Bay , (— BD), 3 Jun 1953, Parker 4872 ( BOL, K, NBG) ; Groot Hagelkraal , ca. 30 m up W. facing limestone cliff, (— DA), 26 Apr 2016, Elliott & Betz TE 2016_020 ( BOL) , Elliott & Betz TE 2016_022 ( BOL) , Elliott & Betz TE 2016_024 ( BOL) , Elliott & Betz TE 2016_029 ( BOL) , Elliott & Betz TE 2016_030 ( BOL) ; Groot Hagelkraal, ca. 1 km W. of limestone cliffs, towards Groot Hagelkraal , (— DA), 26 Apr 2016, Elliott & Betz TE 2016_042 ( BOL) ; Grootbos Private Nature Reserve, Witvoetskloof , 25 Aug 2018, Elliott & Muasya TE 2016_378 ( BOL) ; Soetanysberg, farm Bergplaas , (— DB), 26 Mar 1982, v an Wyk 950 ( NBG) . 3420 (Bredasdorp): off Bredasdorp - Skipskop road, ± 1 km on farm road next to tall fence around Farm Melkkamer , (— AD), 15 May 1984, Fellingham 552 ( NBG [2 sheets]) ; outside of De Hoop Nature Reserve , ca. 900 m N. of main entrance gate, (— AD), 30 Sep 2016, Elliott & Muasya TE 0216_116 ( BOL) , Elliott & Muasya TE 2016_117 ( BOL) ; Hamerkop farm, De Hoop, (— BC), 19 Jun 1984, Fellingham 615 ( NBG, WAG) ; 1 km from Witwater towards sea on Elandspad-Witwater road; (— BD), 18 Jun 1984, Fellingham 602 ( NBG) . 3421 (Riversdale): Albertinia, Ystervarkpunt ( Gouriqua ), ‘ Bysteek heuwel’, (— BC), 8 Sep 1987, Willemse 627 ( NBG) ; ± 2 km from Duivenhoks River Mouth, W. side, (— BD), 25 May 1984, O'Callaghan, Fellingham & van Wyk 387 ( NBG) . 3422 (Mossel Bay): Goukamma River Mouth, 1 km from mouth, (— BB), 23 May 1984, O'Callaghan, Fellingham & van Wyk 110 ( NBG) ; Sedgefield , (— BB), Jan 1956, Martin 9680 ( GRA) . 3423 (Knysna): Lake Pleasant Hotel , (— AA), 13 Jul 1960, Acocks 21,226 ( BM, K) ; Brenton Blue Butterfly Reserve, Knysna Dist. , Path A 2-B2, (— AA), 14 Apr 2003, Edge 57 ( PRE) .

Figures

Fig. 4. Examples of plants from four species of the S.cuspidatus and allies group found in Southern Africa, showing the corresponding inflorescences beneath each plant: A and E—S. cuspidatus; B and F—S.graciliculmis; C and G—S.riparius; and D and H—S.australis. The black scale bar adjacent to the inflorescence in H 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. 16. Documented locations of S. australis.

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. 15. Documented locations of S.riparius.