Schoenus compactus T. L. Elliott & Muasya, S.
Creators: name: Elliott, T. L.
name: Muasya, A. M.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Poales
Cyperaceae
Schoenus
Schoenus compactus

description: 2. Schoenus compactus (Levyns) T.L.Elliott & Muasya, S. African J. Bot. 112: 359 (2017).
Tetraria compacta Levyns, J. S. African Bot. 13: 83 — 85 (1947).
Type: South Africa, Western Cape Province, 3318 (Cape Town): Kirstenbosch, clearing N. of Window Stream, (‒CD), Sep 1945, Esterhuysen 11,808 (BOL, lecto.! [BOL139417], here designated; BM!, BOL! [BOL139416, BOL139418], K! [K000244951, K000244952], PRE! [PRE0099912 -0], BR [BR0000008638946] — image!, MO[MO-1515509] — image!, iso.).
[Note: The lectotype was chosen by T.L. Elliott from three type specimens at BOL, the institution where Levyns worked. These three specimens lacked any indications of which should be the holotype of S. compactus, so a lectotype was designated.].
Caespitose, phyllopodic perennial graminoid with a contracted (i.e. relatively short and congested) inflorescence (Fig. 3G). Culms terete, (304 —)387 — 518(— 865) X (0.5 —) 0.7 — 1.1 mm (Fig. 3B). Leaves basal, less than half the height of culms or more, 1 — 4, (50 —)122 — 210 (— 370) X (0.3 —) 0.5‒0.9 mm, proximally channelled, margin serrate above sheath, usually straight but sometimes curled, firm and somewhat stiff. Sheaths reddish-brown at base but paler above (often with a tinge of orange), firm, longitudinally striate. Ligule firm, lobes obtuse, 0.2 — 0.8(— 1.6) mm long. In fl orescence a relatively short, dense, congested pseudolateral panicle, (11 —)20‒27(— 35) X (4.0 —) 5.5‒8.5(— 12.5) mm, proximal rachis length (2.5 —)6.5‒12.0(— 20.0) mm (Fig 3G). Proximal primary in fl orescence bracts firm, apex acuminate, channelled, sometimes thickened and/or slightly widened base, (21 —)43‒77(‒115) mm long, exceeding length of inflorescence up to several times. Spikes varying in number 2‒15, (6 —)7‒10(— 14) mm long, aggregated into two to three clusters, overlapping. Spikelets lanceolate, (3.7 —)4.5‒5.7(— 7.4) X (0.5 —)0.9‒1.1(— 2.0) mm, pedicellate, 1 — 8 (usually 2 — 4) spikelets per spike, light reddish-brown in colour (Fig. 5B). Proximal spikelet prophyll 1 per spikelet, firm and usually somewhat thickened, often tinged orange (especially when young), with notable, raised vein extending to mucro, (0.2 —)0.6‒1.3(— 2.1) mm long, mucros often very long, (0.8 —)2.6‒4.6(— 7.0) mm long. Rachilla (0.2 —)0.7‒1.6(— 5.1) mm long. Glumes 5‒8 per spikelet, first three glumes usually relatively short, proximal glume (0.8‒)1.0‒1.8 (— 2.8) mm long, subproximal glume (0.8‒)1.6‒2.3(— 3.4) mm long, lower glumes usually scarious, upper glumes often with narrow hyaline margins and longer than basal ones, apex acuminate to acute. Glume mucros varying in length, often thin, proximal mucro (0.1‒) 0.6‒1.1(— 2.9) mm long, subproximal mucro (0‒)0.3‒0.8(— 1.7) mm long. Stamens 2‒3 per floret, anthers 1.0‒ 2.3 mm long. Stigmas 3- branched, vestigial stigmas of second bisexual floret absent (i.e. yet to be observed). Perianth bristles absent (yet to be observed). Nutlet usually broad elliptic, trigonous, yellowish in colour when young and becoming reddish-brown with age, (1.2‒)1.7‒2.7 X 0.6‒1.1(— 1.4) mm (Fig. 6B). Nutlet beak 0.3‒0.6(— 0.9) mm long, hispid.
Flowering: September to February
Distribution and ecology: Schoenus compactus is a species with a relatively small distribution in South Africa, ranging from the Cape Peninsula in the west to the Riviersonderend Mountains in the east (Fig. 8). This species has been collected from elevations ranging from sea level to near 1400 m, generally on coarse-textured soil in the fynbos vegetation type. However, collections have also been made from localities with clay soil, as well as from seepages and moist flats.
Diagnosis: Schoenus compactus is a species with a short, dense, congested (i.e. compact) inflorescence (Fig. 3G), which is similar to S. auritus (see Elliott et al., 2019); however, it does not have the membranaceous sheaths and ligules that are present in S. auritus. Schoenus compactus appears to be closely allied to S. crassus, as both species have thickened and firm primary inflorescence bracts and prophylls, often with a tinge of orange colour (Fig. 3G and H). The main distinguishing character between these two species is the length of the inflorescence, as that of S. compactus is short and congested with the spikes overlapping almost completely, while S. crassus has more of an elongate inflorescence with spikes only partially overlapping. Schoenus compactus is generally a less robust species than S. crassus (Fig. 3B and C).
Pseudo-vivipary, the development of a plantlet adjacent to an inflorescence or a floret within a spikelet (Gordon-Gray et al., 2009), has been observed in several specimens of S. compactus (e.g. Pillans 2935, Levyns 7914, Stokoe s.n. [SAM66595]). Schoenus compactus plants displaying pseudo-vivipary seem to have the same vegetative habit as plants that are not pseudo-viviparous, but they have plantlets growing out of the spikelets.
A shorter form of S. compactus having narrow elliptic nutlets has been collected from the Hottentots Holland Mountains (e.g. Esterhuysen 12,495, Esterhuysen 17,747). Further investigation is required to determine if these collections represent a new species, hybrids or intraspecific variation within S. compactus.
Additional collections examined
South Africa. WESTERN CAPE: 3318 (Cape Town): Camps Bay, (— CD), 28 Oct 1945, Levyns 7914 (BOL); 19 Jan 1947, Levyns 8726 (BOL); Kirstenbosch, (— CD), Dec 1945, Esterhuysen 12,528 (BM, BOL [2 sheets], K); Table Mountain National Park, Klaasenskop, rocky outcrop N. of Klaasenskop beacon, (— CD), 24 Nov 2016, Elliott TE 2016_158 (BOL); Table Mountain National Park, along trail between Skeleton Gorge and Maclear's Beacon, (— CD), 9 May 2018, Elliott & van Mazijk TE 2016_357 (BOL); Table Mountain, (— CD), 24 Jan 1811, Burchell 570 (K); ‘ In summo monte Tabulari’, (— CD), Nov 1879, Bolus 4742 (BOL [2 sheets], K). 3319 (Worcester): Zachariashoek exp. Catchment, Kasteelkloof catchment, (— CC), 10 Jan 1974, Smith 209 (NBG, PRE). 3418 (Simonstown): Plateau on the Muizenberg, (— AB), 26 Sep 1915, Pillans 2935 (BOL [2 sheets]); Noordhoek, (— AB), 1 Nov 1942, Henderson 1276 (NBG); Silvermine Nature Reserve, Steenberg Peak, (— AB), 9 Jun 2002, Verboom 540 (BOL); Silvermine Nature Reserve, along track, ca. 500 m S. of carpark on S. side of road, (— AB), 9 Jun 2002, Verboom 543 (BOL); Silvermine, Noordhoek Peak, fynbos on side of track near top of the mountain, permanent site #35, (— AB), 19 Dec 2016, Euston-Brown 5156 (BOL); Constantiaberg summit, S. of radio mast, permanent monitoring site #46, (— AB), 1 Mar 2017, Euston-Brown 5208 (BOL); Schoesters Kraal, (— AB), 5 Sep 1897, Wolley-Dod 2700 (BM, BOL); near Smitswinkel Bay, (— AD), 7 Dec 1948, Levyns 9317 (BOL); Garslandkloof, Cape of Good Hope Nature Reserve, Plot 227 (— AD), 8 Oct 1966, Taylor 6937 (PRE, NBG); Cape of Good Hope Nature Reserve, along Olifantbos road near plot 29, (— AD), 29 Sep 1978, Taylor 9865 (NBG); Cape of Good Hope Nature Reserve, at plot 50, (— AD), 29 Sep 1978, Taylor 9868 (NBG); Cape of Good Hope Nature Reserve, gravel track from Olifantsbos road to Sirkelsvlei, (— AD), 23 Oct 2005, Verboom 902 (BOL), Verboom 903 (BOL); Cape Point Nature Reserve, on N. side of Circular Drive, ca. 250‒300 m from turn-off of road heading to the Cape of Good Hope, (— AD), 14 Sep 2018, Elliott TE 2016_391 (BOL); Hottentots Holland Triplets, (— BB), 30 Dec 1945, Esterhuysen 12,495 (BOL, NBG); sandy plateau on Pic Sans Nom, Hottentots Holland Mts., (— BB), 8 Jan 1950, Esterhuysen 16,733 (BOL, NBG); Hottentot's Holland, ridge on S.E. flank of Landdroskop, (— BB), 1 Dec 2003, Verboom 674 (BOL); mountain slopes near Palmiet R. mouth, (— BD), 21 Jan 1946, Esterhuysen 12,547 (BOL); Hangklip Estates, (— BD), Nov 1947, Stokoe s.n. (SAM); Palmiet River mouth, (— BD), 28 Nov 1948, Levyns 9310 (BOL); Kogelberg Forest Reserve, Louws River road near Rooi Els, (— BD), 11 Mar 1970, Boucher 1178 (K, NBG); Kogelberg Nature Reserve, along Palmiet River Walk, (— BD), 18 Nov 2016, Elliott & Muasya TE 2016_148 (BOL), Elliott & Muasya TE 2016_149 (BOL), Elliott & Muasya TE 2016_150 (BOL), Elliott & Muasya TE 2016_152 (BOL), Elliott & Muasya TE 2016_153 (BOL); on mountain slope N. of ' Harold Porter National Botanical Garden', along ' Zigzag Trail Path’, (— BD), 29 Nov 2017, Elliott & Smith TE 2016_310 (BOL), Elliott & Smith TE 2016_311 (BOL). 3419 (Caledon): Vijoen's Pass, (— AA), 14 Sep 1947, Levyns 8333 (BOL); Victoria Peak, Hottentots Holland Mountains, (— AA), 15 Oct 1950, Esterhuysen 17,747 (BOL, NBG); Grabouw, Nuweberg, (— AA), 2 Feb 1962, Taylor 3025 (NBG, PRE); Hottentotsholland mountains, W of Landdroskop Hut, 2 km from hut towards Sir Lowry's Pass, (— AA), 27 Feb 1984, Fellingham 484 (NBG); Hottentots Hollands Nature Reserve, ca. 6 km from Nuweberg parking lot, along jeep track to Landdroskop Hut, (— AA), 18 Feb 2017, Elliott TE 2016_176 (BOL); Highlands Forest Reserve, (— AC), 14 Oct 1956, Levyns 10,600 (BOL [2 sheets]); Kogelberg Nature Reserve, near Highlands parking area, (— AC), 17 Nov 2002, Verboom 614 (BOL); Vogelgat Private Nature Reserve, ca. 100‒200 m to S. of Quark House, ca. 20‒30 m downslope of Birdseye / Roadend Trails, (— AD), 24 Aug 2018, Elliott TE 2016_364 (BOL); upper slopes of Riversonder End Peak, (— BB), Nov-Dec 1928, Thorne s.n. (SAM [3 sheets]); Rooi Els, (— BD), 31 Oct 1948, Levyns 9289 (BOL); near Pringle Bay, 3 Jun 1953, Parker 4871 (NBG); Betty's Bay, (— BD), 26 Sep 1966, Dahlstrand 1136 (PRE); Elim, (— DA), 20 Apr 1896, Schlechter 7655 (BM, BOL).
description: Published as part of Elliott, T. L. & Muasya, A. M., 2020, A taxonomic revision of Schoenus cuspidatus and allies (Cyperaceae, tribe Schoeneae) - Part 2, pp. 327-347 in South African Journal of Botany 130 on pages 332-335, DOI: 10.1016/j.sajb.2019.12.015, http://zenodo.org/record/10496754