Schoenus gracillimus 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 : 310-311

8. Schoenus gracillimus T.L.Elliott & Muasya , S. African J. Bot. 112: 360 (2017).

Epischoenus gracilis Levyns, J. S. African Bot. 7: 81 (1941),

non Schoenus gracilis Sw. (1788) .

Type: South Africa, Western Cape Province, 3318 (Cape Town): Biesjevlei , Jonkershoek , (‒DD), 2 Feb 1941, Levyns 7389 ( BOL, holo! [ BOL_139402 ]; K! [ K000244901 ], PRE! [ PRE0099605 ], iso.) .

Caespitose, perennial graminoid, aphyllopodic ( Fig. 4C and 4I ). Culms narrow and ridged, (393 —)512 — 628(‒850) £ 0.2‒0.6 mm, sometimes slightly hairy. Leaves rudimentary if present, (6 —)8 — 13(‒ 15) £ 0.1 mm, straight. Sheaths dark reddish-black, longitudinally striate, open, central vein terminating in a mucro up to several mm long, semi-firm to firm. Ligule usually absent, 1.1‒1.3 mm. In fl orescence a depauperate, pseudolateral panicle, (15 —)18‒21(‒25) £ 2.0‒ 4.0(‒5.0) mm, proximal rachis length 6.0‒10.5(‒13.0) mm ( Figs. 4I and 7H ). Proximal primary in fl orescence bracts (20 —)26‒31(‒51) mm long, narrow, without lateral chartaceous extensions, varying from involute to distally terete, apex acute, exceeding length of inflorescence slightly. Spikes 2‒3 (usually 2), (8 —)10‒12(‒14) mm long, aggregated into small clusters dispersed along rachis, slightly overlapping. Spikelets linear-lanceolate, 1 — 2 spikelets per spike, (5.7 —) 6.5‒7.2(‒8.0) £ 0.9‒1.6 mm, pedicellate, often pendulous, colour ranging from light brown to almost black, texture firm and opaque, sometimes partially hairy, not concealed by primary inflorescence bracts, varying number of sterile glumes at spikelet base ( Fig. 8H ). Proximal spikelet prophyll sometimes present, (0.7 —)2.0‒ 3.4 mm, mucros varying in length, 0‒0.9(‒3.7) mm long when present. Rachilla (0.6‒)1.3‒2.9(‒6.6) mm long. Glumes 4‒7 per spikelet, texture opaque and firm, narrow hyaline margins, lower glumes varying in length, proximal glume (0.6‒)1.1‒2.7(‒3.7) mm long, subproximal glume (1.0‒)1.7‒3.3(‒4.1) mm long, upper glumes longer than basal ones, apex acuminate to obtuse. Glume mucros often absent, proximal mucro 0‒0.5(‒1.4) mm long, subproximal mucro 0‒0.2(‒1.1) mm long. Stamens 3 — 4 (usually 3) per floret, fully developed anthers not observed. Stigmas 3-branched, vestigial stigmas present. Perianth bristles absent (i.e. yet to be observed). Suprafloral axis sometimes thickening and strengthening, eventually curving. Nutlet 2.3 £ 1.1 mm, broad elliptic, trigonous, shiny, yellowish in colour when young and turning reddish-brown with maturity, stipitate or sometimes seated on a cup-like disk; nutlet beak short and broad, 0.1‒0.2 mm ( Fig. 10H ). ( Figs. 4 , 7 , 8 and 10 )

Flowering: August to June

Distribution and ecology: Schoenus gracillimus is predominately a species of damp sites in the Western Cape Province of South Africa ( Fig. 18 ). Most specimens of S. gracillimus have been collected in the mountains (up to 1700 m); however, specimens have also been collected from elevations near sea level.

Diagnosis: The inflorescence of S. gracillimus is depauperate with few spikelets (usually <5), in which some are often pendulous on long pedicels. Similar southern African Schoenus species include S. adnatus , S. crinitus and S. schonlandii , but these species usually do not have the pendulous spikelets of S. gracillimus . In addition, S. crinitus is a much more hairy and rigid species compared to both S. adnatus and S. gracillimus , and the spikelet receptacles of S. adnatus are adnate to the basal bract, whereas those of S. gracillimus are not. Aside from several slight differences in plant growth and spikelet form, the distributions of S. gracillimus and S. schonlandii differ, where S. gracillimus is a species found farther to the west.

The spikelets of S. gracillimus tend to be less pendulous in specimens collected around the Stellenbosch area compared to other regions.

Additional collections examined

South Africa. WESTERN CAPE: 3218 (Clanwilliam): Piketberg Mt., Zebra Kop , (‒DB), 16 Dec 1979, Esterhuysen 35,321 ( BOL) . 3219 (Wuppertal): Boontjies Kloof , (‒AA), Dec 1941, Stokoe s.n. ( SAM) ; Cedarberg Mts., between Pakhuis & Heuning Vlei, (‒AA), 28 Dec 1941, Esterhuysen 7457 (BOL, NBG); Heuning Vlei , (‒AA), Jan 1942, Stokoe s. n. ( SAM) ; Cedarberg, Boontjies Vlei , (‒AA), Sep 1942, Stokoe s.n. ( SAM) ; N Cederbergen , damp stream-bank along path from Pakhuis to Heuning Vlei , (‒AA), 19 Oct 1945, Esterhuysen 12,054 ( BOL [2 sheets], NBG) ; N Cederbergen , wet bank at Boontjieskloof , (‒AA), 24 Oct 1945, Esterhuysen 12,215 ( BOL) ; Groenberg near Cederberg at Pakhuis , (‒AA), 27 Dec 1956, Esterhuysen 26,860 ( BOL) ; Cederberg Wilderness Area, along R364, Rocklands area , (‒AA), 14 Jul 2016, Elliott & Muasya TE 2016_094 ( BOL) ; Cedarberg, (‒AC), 1 Mar 1932, Stokoe 9286 ( BOL [2 sheets]) ; Cederberg Mts. , Middelberg , (‒AC), 22 Jun 1942, Esterhuysen 7858 ( BOL, NBG) ; S Cederbergen , Duiwelsgat ( Sneeuberg area ), (‒AC), 11 Oct 1946, Esterhuysen 13,121 ( BOL) ; c. 1 km NW of Sneeuberg , hut along path, then down slope, (‒AC), 24 Nov 1986, Taylor 11,687 ( NBG) ; Cederberg, near Sneeuberg hut, (‒ AC), 6 Apr 2002, Verboom 521 ( BOL) ; Cederberg Wilderness Area , several km to E of Cederberg Algeria Wilderness Cottages and Uitkyk, in direction towards Matjiesrivier Nature Reserve , (‒AC), 13 Jul 2016, Elliott & Muasya TE 2016_076 ( BOL) . 3318 (Cape Town): S slopes above ravine on Helderberg , (‒BB), 14 Nov 1948, Esterhuysen 14,657 ( BOL [2 sheets], NBG) ; Kirstenbosch , beside trickle of water on lower sandy part of clearing N of Window, (‒CD), Sep 1945, Esterhuysen 11,812 ( BOL, NBG, SAM) ; Kirstenbosch , C.P., N of Window stream, (‒ CD), 10 Mar 1948, Esterhuysen 14,398 ( BOL, NBG) ; Table Mt. , marsh on W slopes between Bakoven & Llandudno , (‒CD), 26 May 1949, Esterhuysen 15,397 ( BOL, GRA) ; Paardenberg , (‒DB), 20 Nov 1997, Muasya & Verboom 1213 ( K, NBG) ; E slopes of Buller's Kop , Gt. Drakenstein Mts. , (‒DD), 30 Sep 1945, Esterhuysen 11,905 ( BOL, NBG) ; stream bank on steep upper S slopes of Guardian Peak , (‒DD), 7 Oct 1945, Esterhuysen 11,995 ( K) ; Stellenbosch Div. , gully on SE side of shale band, (‒DD), 30 Dec 1945, Esterhuysen 12,498 ( BOL) ; Jonkershoek , (‒DD), 23 Nov 1951, Parker 4686 ( NBG) ; Jonkershoek Nature Reserve, c. 200 — 300 m downslope of junction of Panorama and Swartboskloof trails, (‒DD), 22 Sep 2017, Elliott & Muasya TE 2016_104 ( BOL) , Elliott & Muasya TE 2016_105 ( BOL) , Elliott & Muasya TE 2016_106 ( BOL) , Elliott & Muasya TE 2016_110 ( BOL) . 3319 (Worcester): plateau on 24 Rivers Mts. above Porterville , (‒AA), 23 Oct 1949, Esterhuysen 16,204 ( BOL) ; Groot Winterhoek , De Tronk, (‒ AA), 29 Dec 1979, Low 894 ( NBG) ; 3 Apr 1981, Low 1135 ( NBG) , Low 1136 ( NBG) ; Groot Winterhoek Reserve , trail from parking area to De Tronk, (‒AA), 26 Nov 2002, Verboom 634 ( BOL) , Verboom 636 ( BOL) ; Groot Winterhoek Wilderness Area, on edge of trail near Disa Pool , c. 1 km from parking lot, (‒AA), 20 Oct 2018, Elliott TE 2016_409 ( BOL) ; 28 Sep 2019, Elliott TE2016_434 ( BOL) ; Elands Kloof, (‒AC), 13 Dec 1946, Levyns 8096 (BOL, PRE, SAM); Elands Kloof , near river, (‒AC), 13 Dec 1946, Levyns 8100 ( BOL) ; Elands Kloof , (‒AC), 15 Dec 1946, Levyns 8122 ( BOL) ; 3 Apr 1948, Levyns 9241 ( BOL) ; 17 Dec 1948, Levyns 9339 ( BOL) ; Elandskloof area , 1 km S of church, (‒AC), 26 Apr 2017 Elliott, Muasya & Betz TE 2016_181 ( BOL) ; upper reaches of Witels Kloof , (‒ AD), 8 Oct 1953, Esterhuysen 21,853 ( BOL) ; Hex River Mountains, along inflow stream draining into Eselfontein dam, Eselfontein farm, (‒AD), 9 Sep 2018, Elliott TE 2016_388 ( BOL) ; Suurvlakte , (‒CA), 31 Mar 1945, Esterhuysen 11,534 ( BOL) ; Suurvlakte , between Haweqwas & Krom R. Pk., (‒CA), 9 Dec 1945, Esterhuysen 12,337 ( BOL) ; gully on S side of Lower Wellington Sneeuwkop, (‒CA), 23 Dec 1945, Esterhuysen 12,443 (BOL, NBG, SAM); near spring on SE slopes of Molenaarsberg , (‒CA), 5 Oct 1947, Esterhuysen 14,088 ( BOL) ; Witteberg, Slanghoek Mts., on upper rocky W slopes, (‒CA), 13 Nov 1949, Esterhuysen 16,512 (BOL, NBG); SW side of the Witteberg, Slanghoek Mts. , (‒CA), 13 Nov 1949, Esterhuysen 16,525 ( BOL) ; S side of Du Toits Pk., (‒CA), 27 Dec 1949, Esterhuysen 16,650 ( BOL) ; Du Toit's Kloof, Worcester end, (‒CA), 11 Jan 1952, Esterhuysen 19,883 (BOL, NBG); Bainskloof , (‒CA), 25 Sep 1956, Esterhuysen 26,300 ( BOL) ; Baineskloof Tweede Tol , (‒CA), 7 May 1982, Getliffe 1070 ( NU) ; Limietberg Nature Reserve , growing on SE facing slope of R301, c. 2 km to NE of Bainskloof community, (‒CA), 25 Jun 2017, Elliott & Muasya TE 2016_206 ( BOL) ; Limietberg Nature Reserve , near small creek that passes under R301 c. 3 km SW of Bainskloof community, (‒CA), 25 Jun 2017, Elliott & Muasya TE 2016_214 ( BOL) ; Limietberg Nature Reserve, along Bobbejaansrivier hiking trail, c. 1.25 km before waterfall, (‒CA), 1 May 2018, Elliott, Muasya & van Mazijk TE 2016_344 ( BOL) , Elliott, Muasya & van Mazijk TE 2016_345 ( BOL) , Elliott, Muasya & van Mazijk TE 2016_346 ( BOL) ; marsh on W slopes of Chavonnesberg , (‒CB), 3 Oct 1948, Esterhuysen 14,590 ( BOL) ; Waaihoek Mts., Sentinel stream swamp, (‒CB), 2 Nov 1953, Esterhuysen 22,219 ( BOL) ; Gem Kloof, S side of Fransch Hoek Mts., 2 — 3 m from foot of Pass , (‒CC), 11 Feb 1945, Esterhuysen 11,416 ( BOL) ; SE side of French Hoek Mtns. , (‒CC), Jan 1949, Stokoe s.n. ( SAM) ; Klein Drakenstein Mountains, Kasteelkloof Experimental Catchment, (‒CC), 8 Oct 1970, Kruger 1054 (NBG, PRE); Klein Drakenstein Mountains , Kasteelkloof Catchment , (‒CC), 3 Nov 1971, Kruger 1488 ( NBG) ; Drakenstein Mountains, 11 km W of Franschhoek, above L'Ormarins waterfall, (‒CC), 26 Oct 2012, Helme 7463 ( SAM) ; French Hoek , (‒CC), 21 Nov 1896, Schlechter 9334 ( BR) ; Blaaskloof , W slopes of Keeromsberg, (‒DA), 23 Feb 1958, Esterhuysen 27,597 ( BOL, NBG [2 sheets], PRE) . 3320 (Montagu): Marloth Nature Reserve , c. 1 — 1.25 km to W of Goedgeloof Hut, growing on W side of Grootrivier , (‒CD), 17 Sep 2018, Elliott & van Mazijk TE 2016_404 ( BOL) . 3321 (Ladismith): Garcia Forest Station at foot of Langeberge , (‒CC), 25 May 1950, Esterhuysen 17,252 ( BOL) . 3322 (Oudtshoorn): George, Forest Reserve , (‒CD), 3 Aug 1956, Levyns 10,573 ( BOL) ; Cradocksberg , on steep SE slope at head of kloof, (‒CD), 14 Apr 1963, Esterhuysen 30,154 ( BOL) . 3418 ( Simonstown ): marshy stream-side in the valley between Vlakkenberg & Constantiaberg, (‒AB), 21 Mar 1976, Esterhuysen 34,216 ( BOL) ; Somerset Sneeuwkop , (‒BB), 12 Mar 1937, Stokoe 5008 ( BOL) ; Triplets, Somerset West, (‒BB), 13 Dec 1942, Esterhuysen 8255 (BOL, NBG, PRE); Somerset Sneeuwkop , (‒BB), Feb 1943, Stokoe s.n. ( SAM) ; E slopes of Hottentot Holland Mtns, near Somerset Sneeuwkop , (‒BB), Sep 1948, Stokoe s.n. ( SAM) ; Pringle Bay Flats N of Groot Hangklip, Plot 300/7, (‒BD), 12 Jan 1970, Boucher 1059 ( NBG) . 3419 (Caledon): Lebanon Catchment Ig., (‒AA), 3 Nov 1966, Kruger 170 ( NBG) ; Lebanon Catch. IId, (‒AA), 21 Sep 1967, Kruger 516 ( NBG) ; Jonkershoek State Forest, Disavlei Raingauge , (‒ AA), 9 Jan 1973, Haynes & Kruger 734 ( NBG) ; Hottentot's Holland, S aspect of Landdroskop , (‒AA), 1 Dec 2003, Verboom 673 ( BOL) ; Hottentots Hollands Nature Reserve, c. 1 — 1.25 km from Nuweberg parking lot, along jeep track to Landdroskop Hut , (‒AA), 18 Feb 2017, Elliott & Muasya TE 2016_171 ( BOL) ; Hottentots Holland Mountains, Boesmanskloof , TMGA seep monitoring site T6_1b, (‒AA), 19 Oct 2018, Euston-Brown ( BOL) ; Elgin Basin, Arieskraal Farm (portion Solva ), at the S boundary, the road crossing a small tributary of the Palmiet River , (‒AC), 23 Feb 1996, Rode 636 ( NBG) ; Shaw's Mt. near Hermanus , (‒AD), 23 Oct 1949, Levyns 9496 ( BOL) ; Genadendal Mtns. , (‒BA), Nov 1930, Stokoe s.n. ( BOL) .

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. 18. Documented locations of S.gracillimus.