Schoenus graminifolius (Levyns) T.L.Elliott & Muasya, S.

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 : 525

2. Schoenus graminifolius (Levyns) T.L.Elliott & Muasya, S. African J. Bot. 112: 359 (2017).

Tetraria graminifolia Levyns, J. S. African Bot. 13: 85 (1947).

Type: South Africa, Western Cape Province, 3318 (Cape Town): Lion's Head, western slopes, (–CD), 29 Jul 1946, Levyns 7917 (BOL!, holo. [ BOL139426 ]).

Caespitose, phyllopodic perennial graminoid. Culms terete, 290–650 × 0.6–1.4 mm. Leaves basal, up to height of culm, 2–5, (150–)283–410 × 0.2–0.6(—1.9) mm, usually straight, proximally channelled or not, margin serrate above sheath. Sheaths firm, reddish-brown but paler above, longitudinally striate. Ligule ranging from scarcely membranaceous to membranaceous with small reddish-purple streaks, 2-lobed, varying in length, (0.5–)1.1–2.5(—5.6) mm long. In fl orescence a contracted pseudolateral panicle, 20–39 × 7–15 mm, proximal rachis length usually relatively short, (1–) 4–15 mm. Proximal primary in fl orescence bracts sometimes channelled proximally, apex acute to acuminate, widened at base, 90–165 mm long, exceeding length of inflorescence up to several times, notable longitudinal veins. Proximal and subproximal primary inflorescence bracts with membranaceous extensions at base. Spikes 2–5, (3.0–)7.0– 19 mm long, overlapping. Spikelets lanceolate, 5.2–7.1 × 1.1–1.4 mm, pedicellate, 2–11 spikelets per spike, membranaceous or chaffy in texture. Proximal spikelet prophyll often indistinguishable from lower glumes, with a raised vein extending to mucro, 1.4–3.0(— 4.4) mm long, chaffy, prophyll mucro 1.3–3.6 mm long. Rachilla 0.1–2.4 mm long. Glumes 4–7 per spikelet, proximal glume relatively long, (2.0–) 3.4–4.4 mm long, subproximal glume 3.6–5.3 mm long, upper glumes longer than basal ones, apex obtuse. Glume mucros absent or short, proximal mucro 0.1–1.6 mm long, subproximal mucro 0.1–0.4(—1.7) mm long, lower glumes and mucros usually over half the length of spikelet. Stamens (2–)3(—4) per floret, anthers not measured due to lack of specimens at anthesis. Stigmas 3-branched, vestigial stigmas of second bisexual floret not observed. Perianth bristles about half the length of nutlet. Nutlet broad elliptic, trigonous, yellowish in colour, 1.4–2.3 × 1.0– 1.1 mm. Nutlet beak, 0.3–1.0 mm long, hispid ( Figs. 2 and 3 ).

Flowering: Flowering specimens not observed, but fruiting occurs from July to November

Distribution and ecology: Schoenus graminifolius has been collected from slopes on Lion's Head and Chapman's Peak on the Cape Peninsula ( Fig. 8 ). This species has been mostly found on granitic soils at elevations greater than 120 m.

Diagnosis: The spikelets of S.graminifolius differ from other species in the group as the glumes are papery (or chaffy) with reddish-purple streaks throughout and the apices are usually obtuse. The glumes of the other species in this group are firmer (see Fig. 3 ), without distinct reddish-purple streaks throughout. The primary inflorescence bracts of S. graminifolius are conspicuously widened at the base, which is similar to S. auritus ; however, the notable differences in the glumes can be used to distinguish the two species from each other.

Additional collections examined

South Africa. WESTERN CAPE: 3318 (Cape Town): W. slopes below Lion's Head , (–CD), Oct 1946, Levyns 8092 ( BOL, K, SAM); Signal Hill, circular path below Lion's Head, N.W.-facing aspect above Clifton , (–CD), 5 Nov 2005, Verboom 905 ( BOL); c. 600 m from Signal Hill Rd. along hiking path to Lion's Head , at least 100 m away from large granitic outcrop, (– CD), 15 Nov 2017, Elliott & Laidler TE2016_282 ( BOL), Elliott & Laidler TE2016_283 ( BOL). 3418 (Simonstown): Chapmans peak drive, just before the day pass turn around point, below the road, permanent monitoring site # 11, (–AB), 25 Jan 2017, Euston-Brown 5194 ( MT).

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.3. Examples of plants from six species of the Schoenus cuspidatus and allies group found in southern Africa,showing the corresponding inflorescences andspikelets beneath each plant: A, G and M—S.auritus; B, H and N—S.graminifolius; C, I and O—S. ligulatus; D,J, and P—S.exilis; E,K and Q—S.bolusii; and F, L and R—S.submarginalis. 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. 8. Documented locations of Schoenus graminifolius.