Schoenus bolusii (C.B.Clarke) 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 : 528-529

5. Schoenus bolusii (C.B.Clarke) T.L.Elliott & Muasya , comb. nov.

Tetraria bolusii C.B.Clarke in W.T. Thiselton-Dyer, Fl. Capensis 7: 279 (1898), as ‘ T. Bolusi’.

Type: South Africa, Western Cape Province, 3419 (Caledon): ‘ Mont. Hottentotsholland prope Grabouw’, (–AA), Dec 1877, Bolus 4230 (K[ K000244913 ], lecto.!, here designated; BOL! [ BOL5066 ], isolecto.).

[Note: In the protologue of T. bolusii, Clarke (1898) cited the following specimens: Bolus 4230, Ecklon and Zeyher 112, Rehmann 919, Rehmann 921 and Brown s.n. Of these specimens, T.L. Elliott had the opportunity to examine Bolus 4230 (BOL, K) and Rehmann 921 (BM), of which the latter is likely a specimen of Schoenus compactus (Levyns) T.L.Elliott & Muasya ].

Tetraria bolusii C.B.Clarke in T.A. Durand & H. Schinz, Consp. Fl. Afric. 5: 659 (1894), as ‘ T. Bolusi ’, nom. nud. Schoenus bolusii (C.B.Clarke) T.L. Elliott & Muasya, S. African J. Bot. 112: 359 (2017) , nom. inval. [Note: While this place of publication is listed in Index Kewensis , no description was provided, so it is a nomen nudum. The name was validated by Clarke (1898). This means that the comb. nov. provided by Elliott & Muasya (2017) was based on an incorrect basionym, so it was invalid as it was not a ‘correctable error’. The new combination is validated here].

Caespitose, phyllopodic perennial graminoid. Culms terete, slender, (166–)249–310(—460) × 0.3–0.6(—0.7) mm. Leaves basal, 1–3, (12–) 57–100(—278) × 0.2–0.6(—1.4) mm, often curled with age, proximally channelled, margin usually serrate above sheath. Sheaths membranaceous with small reddish-purple streaks ( Fig. 13A ), usually loosely clasping culm, sometimes longitudinally striate. Ligule membranaceous with small reddish-purple streaks, varying in length, (0.2–)0.6–2.2(—5.6) mm long. In fl orescence a slender pseudolateral panicle, (12–)19–26(—35) × (2–)4–6(—11) mm, proximal rachis (2–) 6–11(—18) mm long. Proximal primary in fl orescence bracts slender, not channelled, apex acute, never widened at base, 24–40(—66) mm long, exceeding length of inflorescence 0.5 times or more, without notable longitudinal veins. Proximal and subproximal primary inflorescence bracts never with membranaceous extensions at base. Spikes 2–7(—9), (2.5–)7.0–10.0(—24.0) mm long, sometimes overlapping. Spikelets lanceolate to slightly ovate, short, (2.4–)2.8–3.6 × (0.6–) 0.9–1.2 mm, pedicellate, 2–6(—7) spikelets per spike, reddish-brown with hyaline margins having adjacent small reddish-brown streaks ( Fig. 3E ). Proximal spikelet prophyll 1 per spikelet, with a raised vein extending to mucro, (0.3–)0.4–0.7(—1.1) mm long, prophyll mucro varying in length, (0.7–)2.0–2.5(—5.4) mm long. Rachilla (0.3–)1.0–2.2(—3.4) mm long. Glumes 4–7 per spikelet, proximal glume (0.4–)0.6–1.0(—1.7) mm long, subproximal glume (0.5–)0.9–1.2(—2.1) mm long, upper glumes longer than basal ones, apex acute to acuminate. Glume mucros usually relatively short, proximal mucro 0.1–0.6(—1.2) mm long, subproximal mucro 0.2–0.4(—0.7) mm long. Stamens 3(—4) per floret, 3(—6) per spikelet, anthers 1.3–3.7 mm long. Stigmas 3-branched, vestigial stigmas of second bisexual floret often present. Perianth bristles not observed. Nutlet broad elliptic, trigonous, yellowish in colour, (1.2–)1.3–1.9 × 0.5–1.0(—1.2) mm. Nutlet beak 0.4–0.6 mm long, hispid ( Figs. 2 and 3 ).

Flowering: November–May

Distribution and ecology: Schoenus bolusii is a species of the Western Cape Province of South Africa, ranging from Koue Bokkeveld Valley south to the Caledon and Bredasdorp areas ( Fig. 14 ). However, specimens of this species have not been recorded in the Cape Peninsula region. The elevational range of S. bolusii varies from sites near sea level to mountainous localities close to 1000 m in elevation. Although S. bolusii has been mostly recorded from dry sites on coarse soils, it has also been collected from wet mountain slopes.

Diagnosis: Major diagnostic characters of Schoenus bolusii include its relatively short (<4.0 mm) and narrow spikelets (<1.2 mm), as well as the small reddish-purple streaks adjacent to its glume margins and membranaceous leaf sheaths. Schoenus exilis , S. ligulatus , and S. quartziticus also have narrow spikelets; however, these three species do not have hyaline glume margins with adjacent reddish-purple streaks and leaf sheaths with a similar streaking pattern. Schoenus submarginalis is most similar to S. bolusii , but the leaf sheaths of these two species differ ( Fig. 13 ), with S. submarginalis having firm leaf sheaths that are generally solid in colour, while S. bolusii has membranaceous leaf sheaths with reddish-purple streaks.

Additional collections examined

South Africa. WESTERN CAPE: 3219 (Wuppertal): Witzenberg, Farm Rietfontein , Koue Bokkeveld Valley , (–CD), 28 Jan 2006, Low 9848 ( GRA) . 3318 (Cape Town): Paardeberg, Elgin , (–DB), 23 Nov 1947, Levyns 8778 ( BOL [3 sheets]) . 3319 (Worcester): Tulbagh , (–AC), without date, Zeyher s.n. ( SAM) ; E. slopes Prospect Peak, Hex River Mts. , (– BC), 31 May 1949, Esterhuysen 15,417 ( BOL, K, NBG) ; easterly and northerly slope on farms Doolhof and Foscenberg , (–CA), 20 May 1963, Taylor 4793 ( NBG) ; Onklaar Berg , (–DC), Apr 1926, Stokoe 9445 ( BOL) . 3320 (Montagu): ‘ In liv. mont. Langebergen pr. Swellendam’ , (–DD), 11 Jan 1893, Schlechter 2065 (K) . 3418 (Simonstown): Somerset Sneeukop , (–BB), 12 Mar 1937, Stokoe 5002 ( BOL) ; Palmiet River , (–BD), Feb 1946, Levyns 7921 ( BOL) ; Palmiet River Mts., near Platberg , (–BD), Apr 1947, Stokoe s.n. ( SAM) ; Palmiet River mouth, (–BD), 16 Feb 1948, Levyns 8804 ( BOL [2 sheets]) ; 17 Feb 1948, Levyns 8810 ( BOL [2 sheets]) ; 6 May 1948, Levyns 8892 ( BOL [2 sheets]), Levyns 8893 ( BM) ; Kogelberg State Forest, Research Site , (–BD), Dec 1980, Le Maitre 209 ( NBG) ; Kogelberg State Forest, Research Site 3418BD/3, (–BD), Dec 1980, Le Maitre 219 ( NBG, PRE) ; Palmiet River mouth, E. bank of mouth, (–BD), 27 Apr 2016, Elliott & Betz TE 2016_043 ( BOL) , Elliott & Betz TE 2016_048 ( BOL) ; Kogelberg Nature Reserve, along Palmiet River Walk, (–BD), 18 Nov 2016, Elliott & Muasya TE 2016_142 ( BOL) , Elliott & Muasya TE 2016_143 ( BOL) ; on mountain slope N. of Harold Porter National Botanical Garden, along Zigzag Trail Path , (–BD), 29 Nov 2017, Elliott & Smith TE 2016_308 ( BOL) , Elliott & Smith TE 2016_309 ( BOL) . 3419 (Caledon): Howhoek , (–AA), 4 Feb 1896, Schlechter 7341 ( BM, BOL, GRA, K, NSW, SAM, WAG) ; top of mountains, W. of Viljoen's Pass , (– AA), Nov 1942, Stokoe 8686 ( BOL) ; Elgin , (–AA), 14 Nov 1948, Levyns 9295 ( BOL) ; Lebanon, Catchment Ib , (–AA), Dec 1966, Kruger KR 279 (K, NBG) ; Lebanon Forest Catchment area , (–AA), Dec 1966, Kruger KR 392 ( BOL, PRE) ; Lebanon: catchment Ig , (–AA), Nov 1967, Kruger KR 570 (K, NBG) ; Houhoek, Houtech terrain, river bank near farm, (–AA), 15 Dec 1987, Boucher & Stindt 5349 ( NBG) ; Kleinmond , (–AC), 20 Jan 1950, de Vos 1559 ( NBG) ; Grabouw, Highlands Forest Reserve, Perdeberg , (–AC), 3 Mar 2002, Verboom 510 ( BOL) ; Kogelberg Nature Reserve, near Highlands parking area, (–AC), 17 Nov 2002, Verboom 608 ( BOL) ; Fernkloof Nature Reserve, along Klipspringer Path , (–AC), 10 Feb 2017, Elliott TE 2016_162 ( BOL) ; Vogelgat near Vogelpool , (– AD), 9 Mar 1978, Williams 2444 (K [2 sheets], NBG, PRE) ; Vogelgat above Diosma, W. slopes of kloof, (–AD), 3 Oct 1982, Williams 3208 (K, NBG) ; Vogelgat Nature Reserve , about 100–200 m past ‘die mond’ view, (–AD), 25 Apr 2016, Elliott & Betz TE 2016_001 ( BOL) , Elliott & Betz TE 2016_002 ( BOL) , Elliott & Betz TE 2016_003 ( BOL) , Elliott & Betz TE 2016_004 ( BOL) , Elliott & Betz TE 2016_005 ( BOL) , Elliott & Betz TE 2016_006 ( BOL) ; Betty's Bay, Leopard Gorge , (–BD), 24 Nov 1997, Muasya & Hawkins 1234 (K, NBG) ; Kogelberg Nature Reserve, near Highlands parking area, (–DB), 17 Nov 2002, Verboom 606 ( BOL) . 3420 (Bredasdorp): De Hoop Nature Reserve, Potberg Mountain , (–BC), 30 Nov 2017, Elliott & Smith TE 2016_324 ( BOL) , Elliott & Smith TE 2016_326 ( BOL) , Elliott & Smith TE 2016_329 ( BOL) .

Figures

Fig. 13. Upper sheath and ligule of Schoenus bolusii (A) and S.submarginalis (B).The black scale bar represents 1 mm.

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.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. 14. Documented locations of Schoenus bolusii.