Bulbostylis abortiva (Steud.) C.B.Clarke

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

Type

Type: Madagascar, Nosy Be [Nossibé], Boivin 1996 (P, holo.; K!, iso.)

Morphology General Habit

Tufted annual 15–50(–80) cm tall.

Morphology Stem

Stems up to 1.5 mm thick, deeply grooved, usually with dense short white spine-like hairs

Morphology Leaves

Leaves up to 20 cm long and 0.5 mm wide, flat and channeled, with similar spine-like hairs.

Morphology Leaves Leaf sheaths

Sheaths with slender hairs up to 15 mm long

Morphology Reproductive morphology Inflorescences

Inflorescence open and umbelliform with (10–)20–40(–60) spikelets; main inflorescence bracts 5–60 mm long, the longest much longer than the nearest spikelet, with long slender marginal hairs at the base and short spine-like hairs above.

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets 3–7 mm long, 1–2 mm wide.

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes reddish brown with pale midrib, broadly ovate, 1–2 mm long with translucent 0.2–0.3 mm wide margin with short hairs, obtuse to rounded at apex or lower ones shortly subulate or acuminate, midrib 3-veined, 1–2 mm wide

Morphology Reproductive morphology Fruits

Nutlet at first uncoloured but grey or yellow-brown at maturity, obovoid, 0.7–0.8 mm long, almost smooth or with a translucent surface layer which breaks up into square or circular scales, giving a sometimes tuberculate appearance; epidermal cells isodiametric with strongly sinuose walls.

Morphology Reproductive morphology Flowers Gynoecium Style

Style-base persisting as a brownish knob.

Ecology

Shallow soil over rock, grassland, seasonally moist hollows, cultivation, miombo woodland; 50—2000 m

Note

I am not certain of the Kenya Coast record. C.B. Clarke thought it matched his Bulbostylis coleotricha var. lanifera (Boeck.) C.B. Clarke but Bodard has suggested it is nearer B. abortiva and Hooper states it does not match West African lanifera.

Distribution

Range: Throughout tropical Africa and Madagascar Flora districts: U1 U2 U3 K3 K 7 (see Note)T2 T4 T6 T ?8

Cyperaceae, Miss S. S. Hooper. Flora of West Tropical Africa 3:2. 1972

Diagnostic

Readily distinguished from B. congolensis and large forms of B. densa which it resembles in size, by the ciliate-edged bracts and glabrous glumes

Ecology

Grassland, and cultivated and waste places.

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

Madagascar, Nossibé, n.d., Boivin 1996 (P holotype, K).

Morphology General Habit

Short to medium tufted annual, occasionally up to 80 cm

Morphology Leaves

Leaves of varying height; leaf sheaths scabrid or not, with long white spreading hairs added, especially from mouth, ligule 0; leaf blades 20 cm long, mostly setaceous, often curled and twisted

Morphology Culms

Culms deeply grooved, usually with short white scabrid pubescence, sometimes glabrous

Morphology Reproductive morphology Inflorescences

Inflorescence anthelate, compound, open, of (10)20–40(60) mostly pedicelled spikelets; bracts setaceous, lengths variable, usually inconspicuous, occasionally exceeding inflorescence, margins basally long-haired, becoming scabrid upwards

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets 3–7 × 1–2 mm

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes 1.5–3 mm, reddish brown, broadly ovate, glabrous with hyaline slightly fimbriolate margins, upper glume apex rounded, lower shortly mucronate, midrib indistinctly 3-veined

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 3

Morphology Reproductive morphology Flowers Gynoecium Style

Style branches 3, base persistent on nutlet

Morphology Reproductive morphology Fruits

Nutlet 0.7–0.8 × 0.4–0.5 mm, obovoid, trigonous, surface punctulate with papillae in vertical rows, but often appearing smooth due to an outer covering.

Distribution

Zambia, Zimbabwe, Mozambique. Found throughout tropical Africa and Madagascar, Senegal, Sudan, Burundi, Uganda, Kenya, Tanzania and D.R. Congo, but not in South Africa.

Ecology

Sandy soils, old cultivated lands and Brachystegia woodland; 10–1400 m.

Conservation

Widespread; not threatened.

Recognition

Bulbostylis abortiva closely resembles B. tanzaniae – if mature nutlets are examined differences between these two species can be seen, with the former having a slightly larger nutlet with a puncticulate surface.