Schoenus prophyllus 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 : 534

11. Schoenus prophyllus T.L.Elliott & Muasya , sp. nov. Type: South Africa, Western Cape Province, 3419 (Caledon): Groot Hagelkraal , N. edge of crater-like landscape feature, (–DA), 26 Apr 2016, Elliott & Betz TE2016_033 ( BOL!, holo., MT!, NBG!, iso.).

Tetraria sylvatica var. pseudolorea auct. non Kük., Repert. Spec. Nov. Regni. Veg. 29: 188 (1931), p.p., as to Schlechter 10,516 only. [Note: Kükenthal (1931) cited Schlechter 10,516 as an example of Tetraria sylvatica (Nees) C.B.Clarke var. pseudolorea Kük. ; however, we have classified this collection as S. prophyllus . Kükenthal (1931) also cited Schlechter 7385, Bolus 4742 and Schlechter 7655 in his protologue of T. sylvatica var. pseudolorea . Schlechter 7385 has been designated the type of Schoenus pseudoloreus (Kük) T.L.Elliott & Muasya (see Elliott and Muasya, 2018), whereas the other two collections likely represent a third species.].

Caespitose, phyllopodic perennial graminoid. Culms terete, slender, 258–363 × 0.4–0.7 mm. Leaves basal, 1–3(—7), (61–)82–170 × 0.2–1.0 mm, usually curled with age, proximally channelled, margin serrate above sheath. Sheaths firm but often shredding with age, usually loosely clasping culm, longitudinally striate. Ligule firm, 0.3–1.4 mm long. In fl orescence a contracted pseudolateral panicle, 11–23 × 3–7 mm, proximal rachis length usually relatively short, 6–12 mm. Proximal primary in fl orescence bracts slender, brittle, not channelled, apex acute to acuminate, never widened at base, 28–56(—67) 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 3–6, (3.0–)5.0–9.1(—16.0) mm long, overlapping. Spikelets ovate, 2.8–3.0 × 1.0– 1.5 mm, pedicellate, 3–5 spikelets per spike, reddish-brown sometimes with narrow hyaline margins. Proximal spikelet prophyll 1 per spikelet, prophylls with a raised vein extending to mucro, 0.6–1.4 mm long, firm, usually shining, prophyll mucro 2.9–5.0 mm long. Rachilla 0.8–2.8 mm long. Glumes 5–7 per spikelet, proximal glume 0.8–1.3 mm long, subproximal glume 0.9–1.2(—3.8) mm long, upper glumes longer than basal ones, apex acute to acuminate. Glume proximal mucro 0.3–1.6 mm long, subproximal mucro 0.1–1.4 mm long. Stamens 3 per floret, anthers 1.4–2.0(—3.7) mm long. Stigmas (2)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: May

Distribution and ecology: Schoenus prophyllus has been collected from the southern Agulhas Plain region of South Africa, mostly from limestone-derived soils at elevations less than 200 m ( Fig. 20 ).

Diagnosis: The most notable character of S. prophyllus include its well-developed, firm, shiny spikelet prophylls with relatively long mucros compared to other species in this group ( Fig. 4Q ). Similar species to S. prophyllus include S. bolusii , S. calceolus , S. purpurascens and S. submarginalis , which all have short spikelets (generally <4.0 mm). However, the ovate spikelets of S. prophyllus differ in shape from the lanceolate spikelets of S. bolusii and S. submarginalis . In addition, the spikelets of S. prophyllus do not have the conspicuous reddish-purple streaks adjacent to the glume margins like those of S. bolusii and S. submarginalis . Although S. prophyllus also has ovate spikelets, it has basal leaves that curl with age and terete culm bases that differ from the flattened culm bases and straight leaves of S. calceolus ( Fig. 5 ). Finally, S. prophyllus has channelled, usually terete leaf blades compared to the non-channelled and more flat blades found in S. purpurascens (another species with ovate spikelets).

Additional collections examined

South Africa. WESTERN CAPE: 3419 (Caledon): Groot Hagelkraal , c. 30 m up W.-facing limestone cliff and adjacent to limestone rockface, (–DA), 26 Apr 2016, Elliott & Betz TE 2016_021 ( BOL), TE2016 _023 ( BOL), TE2016 _025 ( BOL) ; Groot Hagelkraal , N. edge of crater-like landscape feature, (–DA), 26 Apr 2016, Elliott & Betz TE 2016_033 ( BOL), TE2016 _035 ( BOL) ; Rietfontein Nature Reserve, W. point of Soetanysberg , (–DD), 23 Mar 1982, Fellingham 270 ( NBG, PRE) . 3420 (Bredasdorp): ‘In collibus pone Cape Agulhas’ , (–CC), 27 Apr 1897, Schlechter 10,561 ( BM, GRA, K, PRE, WAG) ; Agulhas , (–CC), 11 Apr 1948, Levyns 8851 ( BOL) .

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. 20. Documented locations of Schoenus prophyllus.

Fig. 5. Culm base of Schoenus calceolus showing culms grouped together by a translucent leaf sheath.The black scale bar adjacent to the base of the culms represents 10 mm.