Schoenoplectiella corymbosa (Roth ex Roem. & Schult.) J.R.Starr & Jim.Mejías

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation

Predicted extinction risk: not threatened. Confidence: confident

Cyperaceae, K Hoenselaar, B. Verdcourt & H. Beentje. Hypolytrum, D Simpson. Fuirena, M Muasya. Flora of Tropical East Africa. 2010

Type

Type: India, ‘in India orientali’, no collector mentioned (Z or BM, holo.)

Morphology General Habit

Perennial herb.

Vegetative Multiplication Rhizomes

Rhizome short, ascending.

Morphology Stem

Stems many, tufted, dark and/or glossy green, 50–360 cm tall, round or sometimes slightly triangular near apex, 2–10 mm thick near base (but outside sheath), ridged, filled with pith; base surrounded by dark scales and leaf sheaths

Morphology Leaves

Leaves absent. Leaf sheaths often splitting, ending in a short lobe

Morphology Reproductive morphology Inflorescences

Inflorescence an anthela with clusters of ± sessile spikelets on very unequal flat stalks 1–4(–12) cm long, rarely a few spikelets solitary and stalked; main inflorescence bract stem-like and continuing in the direction of the stem, 1–5 cm long, rounded and with distinct longitudinal ribs and dark brown or blackened apex.

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets dark or pale brown, ovoid, 3–8 × 1–2.5 mm, acute, occasionally producing viviparous shoots.

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes grey with red-brown spots or patches or reddish brown all over with paler midrib, ovate, 2–4 mm long, apex mucronate, midrib often raised, margin sometimes ciliate, otherwise glabrous or with short spine-like hairs

Morphology Reproductive morphology Flowers Perianth

Perianth segments absent

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 3, with persistent ribbon-like filaments 2.5 mm long.

Morphology Reproductive morphology Flowers Androecium Stamens Anthers

Anther 1–1.4 mm long with crest 0.2–0.5 mm

Morphology Reproductive morphology Flowers Gynoecium Style

Style pale green, (2–)3(–4)-branched, often splitting irregularly

Morphology Reproductive morphology Fruits

Nutlet yellow-white turning dark brown or black, 1.2–2 × 0.9–1.5 mm, smooth

Figures

Fig. 5, p27

Ecology

Lakes (where it may be locally dominant), swamps, pools, streamside marshes, usually in standing water up to 100(–300) cm deep; less often in seasonally flooded grassland or forest margins; 1000–2950 m

Note

Spikelets paler; inflorescence bract rounded with distinct longitudinal Two varieties were kept up by Lye – though he calls them forms, too. Distinctions are as follows: I am not impressed by these so-called differences; there are dark-spikeleted specimens with ridges, and pale-spikeleted ones without. The difference rounded/boat-shaped makes no sense to me – surely both are gutter-shaped with inrolled edges? The differences in habitat suggested in Haines & Lye seem spurious as well, with overlap for specimens that seem unequivocally one ‘variety’ or another. I am therefore uniting the varieties. Var. junciformis is a form with more contracted inflorescences; it is not accepted here as a separate taxon.

Distribution

Range: Mali, Nigeria, Cameroon, Bioko, Congo-Kinshasa, Rwanda, Burundi, Sudan, Ethiopia, Angola and South Africa; Egypt, Madagascar, India Flora districts: U2 U3 U4 K3 K4 K5 K6 T1 T2 T3 T4 T5 T6 T7

J. Browning, K.D. Gordon-Gray†, M. Lock, H. Beentje, K. Vollesen, K. Bauters, C. Archer, I. Larridon, M. Xanthos, P. Vorster, J. Bruhl, K. Wilson and X. Zhang (2020). Flora Zambesiaca Volume: 14: Cyperaceae. M.Á. García, J.R. Timberlake (Eds). Kew Publish

Type

India: “in India orientali”, unknown collector (Z or BM holotype).

Morphology General Habit

Perennial; rhizome abbreviated, 3–4 mm wide when dry; roots numerous, 2 mm wide when dry

Morphology Culms

Culms contiguous, to 400 cm tall, 2–10 mm thick near base, somewhat terete, glabrous

Morphology Leaves

Leaves reduced to 2–3 sheaths obliquely truncate at top, sometimes with scabrid-margined reduced leaf blade

Morphology Reproductive morphology Inflorescences

Inflorescence a pseudolateral head of clusters of sessile spikelets on 1–10 slender, very unequal scabridulous branches, 20–110 mm long (length greater if proliferation occurring); inflorescence bract 20–100 mm, tapering to a sharp point

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets sessile, 5–8(10) × 2–3 mm, ovoid to cylindric, many-flowered, pale straw-coloured, overlaid by streaks of chestnut-brown

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes all fertile, 3–4 (including mucro, 0.12–0.20 mm) × 2–2.5 mm, ovate, keeled, convex; glabrous, lower glume keels and mucros may be hispidulous; margins slightly ciliated on either side of mucro

Morphology Reproductive morphology Flowers Perianth

Perianth 0; rudimentary when present, unequal-Stamens 3, filaments, 0.12–0.7 wide, persistent on mature nutlets

Morphology Reproductive morphology Flowers Gynoecium Style

Style branches 3

Morphology Reproductive morphology Fruits

Nutlet (including beak) 1.3–2 × 0.9–1.4 mm, ovoid to obovoid in outline, trigonous, clearly or faintly rugulose (faces and margins), or smooth, dark-brown or black at maturity.

Distribution

Botswana, Zambia, Zimbabwe, Mozambique, Malawi. Also in W and N Africa, Namibia, South Africa (Free State, Gauteng, KwaZulu- Natal, Limpopo, Mpumalanga, North West, Northern Cape, Western Cape); Indian subcontinent and introduced into Spain.

Ecology

Forms extensive stands in dams where rhizomes generally submerged under 0.5 m of standing water; proliferation common especially where flowering culms dip into water; 900–2200 m.

Conservation

Widespread; not threatened.