Bulbostylis igneotonsa Raymond

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

Zambia, 15 km E of Kasama, 20.xii.1961, Robinson 4732 (Herb. Raymond holotype, K, MTJB).

Morphology General Habit

Perennial 15–60 cm tall; rhizome woody with slightly swollen shoot bases, burnt down to leave stubs of ± equal length, growth arising above these

Morphology Leaves

Leaves variable, usually to 1/3 culm length, occasionally obsolete; leaf sheath mouth sloping, conspicuously long, white-fringed, ligule 0; leaf blades 4–200 × 0.3–1 mm, linear to setaceous, glabrous to densely pilose

Morphology Culms

Culms c. 1 mm thick, stout, terete, ridged and furrowed, glabrous or shortly pilose

Morphology Reproductive morphology Inflorescences

Inflorescence a pale to dark brown terminal head of 2–5 sessile spikelets, occasionally reduced to a single spikelet; bracts 2–4, equalling inflorescence, few to many long white hairs, long-awned

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets 8–12 × 2–4 mm, oblong, acute

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes spiral, 8–9 mm long, golden to dark brown, long-acuminate, glabrous to shortly pubescent, margin ciliate

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 3

Morphology Reproductive morphology Flowers Gynoecium Style

Style 3-angled, glabrous, branches 3

Morphology Reproductive morphology Fruits

Nutlet 2.1–2.3 (including style base) × 1.3–1.6 mm, triangular-rhomboid, angles blunt, crowned by persistent pyramidal base, surface transversely rugose.

Distribution

Zambia, Malawi. Also in Angola and Tanzania.

Ecology

Shallow soil over rocky outcrops, grassland and Brachystegia woodland; 1000–2350 m.

Conservation

Widespread; not threatened.

Note

This species has been collected in burnt grassland, particularly in N Zambia, and may be fire-resistant. Robinson noted on collections 4732 and 4731, collected at the same locality on the same day, that the former had very hairy stems whilst in the latter they were glabrous.

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

Type

Type: Zambia, 15 km E of Kasama, Robinson 4732 (Herb. Raymond, holo.; K!, MTJB, iso.)

Morphology General Habit

Perennial herb 13–60 cm tall with thick strong horizontal rhizome.

Morphology Roots

Roots rigid.

Morphology Stem

Stems many, in all specimens seen the old ones burnt right down leaving stubs of ± equal length on the horizontal rhizome and new leaves and flowering shoots arising from within these burnt bases. Stems 1 mm wide, sulcate, graceful but stiff, glabrous or very shortly pilose.

Morphology Leaves

Leaves with sheaths cinnamon-coloured, short and acute, the mouth with many long multicellular hairs up to 2 cm long, often forming tangled woolly masses

Morphology Reproductive morphology Inflorescences

Inflorescence pale to dark brown, capitate, obturbinate, ± 1 cm long and wide, mostly with long white hairs at the base but sometimes glabrous.

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets 2–5, sessile, oblong, acute.

Morphology Reproductive morphology Inflorescences Bracts

Bracts 2–4, ± equalling the head, long-awned.

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes orange-brown to red-brown, ovate, 8–9 mm long, long-acuminate, glabrous to densely shortly pubescent and often erose-ciliate at the margin

Morphology Reproductive morphology Flowers Gynoecium Stigma

Stigmas 3, thick

Morphology Reproductive morphology Fruits

Nut pale brownish, triangular-rhomboid, 1.5–2.3 mm long, 1 mm wide, the angles blunt, thickened, with transverse rows of raised vertically elongate cells.

Morphology Reproductive morphology Flowers Gynoecium Style

Style base conic, thick, persistent

Ecology

" Brachystegia woodland, rocky grassy places near streams; 1100–1200(–2100) m

Note

This is a fire-resisting species, very common in Zambia but less so in East Africa. Richards 18536 cited above (from 2100 m) has some inflorescences with 1–2 of the spikelets with pedicels 10–15 mm long, not noted in any other material.

Distribution

Flora districts: T4 T7 Range: Angola, Zambia, Malawi

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