Schoenus schonlandii (Turrill) T.L.Elliott & Muasya

Elliott, T. L. & Muasya, A. M., 2020, A taxonomic revision of the Epischoenus group of Schoenus (Cyperaceae, tribe Schoeneae), South African Journal of Botany 135, pp. 296-316 : 312-313

9. Schoenus schonlandii (Turrill) T.L.Elliott & Muasya , S. African J. Bot. 112: 359 (2017).

Tetraria schonlandii Turrill , Bull. Misc. Inform. Kew 1925: 75 (1925).

Type: South Africa, Eastern Cape Province, 3325 (Port Elizabeth): dry slopes near Sanatorium Common , (‒BC), 19 Apr 1919, Schonland 3172 ( GRA, lecto.! [ GRA_0000238-0 ], here designated; K! [ K000244904 ], PRE! [ PRE0102716-0 ], isolecto.) . [Note: Both the specimens from GRA and K have ‘Type’ written on them in handwriting that appears not to belong to Turrill; thus, based on the information available to us, it was not possible to discern if he had designated a holotype. We designate the specimen at GRA as the lectotype, as the key diagnostic characters (the inflorescences) were clearer for us to see, and T.L. Elliott was able to examine that specimen in person.].

Caespitose, perennial graminoid, aphyllopodic ( Fig. 4D and 4J ). Culms (320 —)497 — 951(‒1150) £ (0.3 —)0.5‒0.6(‒1.1) mm. Leaves usually absent, rudimentary if present, (4 —)6 — 12(‒26) £ 0.2 mm, straight, margins serrate, channelled distally. Sheaths reddish-black, longitudinally striate, open, central vein terminating in a mucro up to several mm long, semi-firm to firm. Ligule usually absent, 0.2‒0.6(‒ 1.0) mm. In fl orescence a pseudolateral panicle with few spikelets dispersed throughout, 14‒22(‒34) £ (2.0 —)4.0‒6.0(‒9.0) mm, proximal rachis length (3.5 —)7.0‒10.5(‒17.0) mm ( Figs. 4J and 7I ). Proximal primary in fl orescence bracts (17 —)21‒31(‒45) mm long, narrow, without lateral chartaceous extensions, varying from involute to terete distally, apex acute to obtuse but breaking-off readily, exceeding length of inflorescence slightly. Spikes 1‒2 (usually 2), (6 —)9‒13(‒17) mm long, aggregated into small clusters along rachis, sometimes overlapping. Spikelets lanceolate, 1 — 3 (usually 2) spikelets per spike, (4.2 —)4.8‒7.1(‒8.1) £ (0.9 —)1.1‒1.5(‒2.6) mm, pedicellate, colour reddish-brown, texture chartaceous to firm and opaque, not concealed by primary inflorescence bracts, varying number of sterile glumes at spikelet base ( Fig. 8I ). Proximal spikelet prophyll sometimes present, (1.3 —)2.2‒2.7(‒3.2) mm, mucros 0‒0.5(‒1.1) mm long when present. Rachilla (0.2‒)1.4‒3.4(‒6.9) mm long. Glumes 4‒8 per spikelet, texture chartaceous to opaque and firm, narrow hyaline margins sometimes present, lower glumes relatively short, proximal glume (1.5‒)2.1‒2.6(‒2.9) mm long, subproximal glume (1.4‒)2.1‒ 2.9(‒3.7) mm long, upper glumes longer than basal ones, apex acuminate to obtuse. Glume mucros often absent, proximal mucro 0‒0.5(‒1.7) mm long, subproximal mucro 0‒0.2(‒0.6) mm long. Stamens 3 per floret, anthers 2.1‒2.5(‒2.6) mm long. Stigmas 3- branched, vestigial stigmas absent (i.e. yet to be observed). Perianth bristles absent (i.e. yet to be observed). Thickening and curving of suprafloral axis not observed. Nutlet (1.4‒)1.9‒2.2(‒ 2.5) £ 0.8‒1.1 mm, broad elliptic, trigonous, rugose to shiny, yellowish in colour when young and turning dark reddish black with maturity, sessile; nutlet beak narrow, 0.2‒0.3 mm ( Fig. 10I ). ( Figs. 4 , 7 , 8 and 10 )

Flowering: Two specimens with flowers were observed: one in November and the other in April

Distribution and ecology: Schoenus schonlandii is distributed along the southern coast of South Africa, with specimens having been collected from as far west as the George area to the Zuurberg area in the east ( Fig. 19 ). This species has been collected from dry slopes and ridges, as well as bushy places from elevations ranging from c. 91 m to nearly 1700 m.

Diagnosis: The inflorescence of S. schonlandii has few spikelets scattered throughout the panicle, which resembles S. adnatus , S. crinitus , and S. gracillimus in form ( Figs. 4 and 7 ). Schoenus schonlandii is not hairy as in S. crinitus , nor does it have spikelet receptacles that are adnate to the basal glumes (e.g. S. adnatus ). Compared to S. gracillimus , S. schonlandii is found farther to the east in South Africa, and it does not have the pendulous spikelets that are often found in the former species.

The inflorescence of S. schonlandii also resembles that of S. rigidus ; however, S. schonlandii lacks the chartaceous extensions of the primary inflorescence bracts that are present in that species.

Additional collections examined

South Africa. EASTERN CAPE: 3324 (Steytlerville): S of peak 81, top of Baviaanskloof Mountains to N of Grasnek, Plot #96, (‒CB), 23 Jul 2011, Euston-Brown 1326 ( NBG) . 3424 (Humansdorp): Witte Els Bosch Peak , (‒AA), 15 Nov 1941, Esterhuysen 6764 ( BOL) ; Storms River Bridge, (‒BA), 24 Jul 1956, Levyns 10,483 ( BOL) . WESTERN CAPE: 3322 (Oudtshoorn): Robinson Pass , (‒CC), May 1936, Laughton 111 ( BOL) ; Montagu Pass below Toll house and bridge, (‒CD), 13 June 1944, Fourcade 6402 ( BOL, NBG) ; Kaaimans R. , near George , (‒DC), Nov 1947, Wilman 24,199 ( BOL) ; Oudtshoorn, Ebb and Flow Nature Reserve near E tracer boundary, Releve 4, (‒DC), 12 Nov 1972, Taylor 8311 ( NBG) . 3323 ( Willowmore ): Peak Formosa, in shelter of rocks near summit, (‒DC), 1 Dec 1957, Esterhuysen 27,389 ( BOL) . 3423 (Knysna): Knysna , (‒AA), Mar 1920, Phillips 8 ( GRA) ; Robberg Nature Reserve near second bungalow (plot 1), (‒AB), 29 May 1970, Taylor 7699 (NBG, PRE) .

Figures

Fig. 4. Examples of plants from six species of the Epischoenus group found in southern Africa, showing the corresponding inflorescences beneath each plant: A and G—S.crinitus; B and H—S. adnatus; C and I—S. gracillimus; D and J—S. schonlandii; E and K—S. lucidus; and F and L—S. neovillosus. The black scale bar adjacent to the inflorescence in L represents 10 mm.

Fig. 7. Diagrammatic representations of the inflorescences of 11 species in the Epischoenus group, with spikelets illustrated in dark grey, primary inflorescence bracts in white and chartaceous (membranaceous) lateral extensions of the primary inflorescence bracts in light grey. Illustrations are not drawn to exact scale and stippling represents hairs. Inflorescences of the following species are shown: A—S. dregeanus; B—S. complanatus; C—S. quadrangularis; D—S. selinae; E—S. rigidus; F—S. crinitus; G—S. adnatus; H—S. gracillimus; I—S. schonlandii; J—S. lucidus; and K—S.neovillosus.

Fig. 8. Examples of spikelets from 11 species of the Epischoenus group found in southern Africa: A—S.dregeanus; B—S.complanatus; C—S. quadrangularis; D—S. selinae; E—S.rigidus; F—S.crinitus; G—S.adnatus; H—S.gracillimus; I—S.schonlandii; J—S.lucidus; and K—S.neovillosus. The black scale bar beside K represents 1 mm.

Fig. 10. Examples of nutlets from 11 species of the Epischoenus group found in southern Africa: A—S. dregeanus; B—S.complanatus; C—S. quadrangularis; D—S. selinae; E—S.rigidus; F—S.crinitus; G—S.adnatus; H—S.gracillimus; I—S.schonlandii; J—S.lucidus; and K—S.neovillosus. The black scale bar beside K represents 1 mm. Fully formed, mature nutlets of S.crinitus and S. neovillosus have yet to be observed.

Fig. 19. Documented locations of S. schonlandii.