Bulbostylis Kunth

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

Morphology General Habit

Perennial or annual herbs, mostly sparsely tufted; rhizome woody, variable, usually compact with swollen confluent shoot bases, occasionally elongate in uniseriate or multiseriate rows, less often of uniform thickness throughout

Morphology Leaves

Leaves variable, mostly grass-like, occasionally reduced to sheaths forming a persistent clothing to shoot bases; sheath mouth conspicuously white-bearded to woolly; ligule mostly 0, seldom a ring of short hairs; blades well-developed or reduced to apiculate projections

Morphology Culms

Culms scapose, terete, ridged and furrowed, glabrous to pilose or densely velutinous apically

Morphology Reproductive morphology Inflorescences

Inflorescence a supra-decompound, compound or simple anthela (of up to 90 spikelets) or reduced to a terminal head or single spikelet (very variable within a clone or population)

Morphology Reproductive morphology Inflorescences Bracts

Bracts (2)3(4), mostly only one elongate, others hardly exceeding inflorescence; glabrous to white woolly

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets cylindric/polygonal or compressed, many-flowered, basal glumes mostly early deciduous

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes imbricate, fertile (except lowest 1–2 in perennials), pubescent to sub-glabrous abaxially, apex emarginate to fringed when old or mucronate, florets bisexual, bristles 0

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 3(2)–1

Morphology Reproductive morphology Flowers Gynoecium Style

Style filiform, glabrous to villous, swollen basally into a pyramidal, more often rounded, vertically compressed, hardened base mostly persistent on nutlet post-dispersal-Nutlets trigonous (perennials) or dorsiventrally convex (annuals), elliptic to oblanceolate in outline; surface reticulate, transversely lineolate and/or ridged, etuberculate; epidermal cells mostly longitudinally (seldom transversely) elongate, sometimes becoming puncticulate.

Distribution

A genus of about 100 species found throughout the tropics; abundant in the grasslands of sub-Saharan Africa.

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

Morphology General Habit

Annual or perennial herbs

Morphology Culms

Culms stems scapose, rarely many-noded

Morphology Leaves

Leaves usually with well developed blades, rarely reduced to sheaths.

Morphology Leaves Leaf sheaths

Sheaths usually with 2 lateral tufts of hairs

Morphology Reproductive morphology Inflorescences Bracts

Involucral bracts leaf-like or glume-like

Morphology Reproductive morphology Inflorescences

Inflorescence usually lax but frequently a compact head of spikelets or sometimes reduced to a single spikelet.

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes spirally arranged, pale to almost black, often with a green midrib, sometimes distinctly mucronate or awned, glabrous to pubescent or scabrid

Morphology Reproductive morphology Flowers Perianth

Perianth absent

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 1–3.

Morphology Reproductive morphology Flowers Gynoecium Style

Style with 1–3 stigmas Style base enlarged, usually persistent as a small knob or in a few species deciduous.

Morphology Reproductive morphology Fruits

Nutlets obovoid to obconic, usually ± trigonous, with various sculpturing.

Note

About 100 species thoughout the tropics; in the flora area 52 species have been recognised. Lye in Mitt. Bot. Staatss. München 10: 539–547 (1971) and Goetghebeur & Coudijzer in B.J.B.B. 55: 207–259 (1985) have discussed the concept of the genus. In Haines & Lye, Sedges & Rushes of E. Afr. (1983) a curious dual nomenclature quite contrary to the Code is employed when each species has one name in Abildgaardia and another in Bulbostylis, both treated as correct names; which is not permissible. The names using the genus Bulbostylis are accepted here but the Abildgaardia names treated in the synonymy. Later in Fl. Eth. Lye treated Abildgaardia and Bulbostylis separately, as did Gordon-Gray in Strelitzia 2 (1995); this is followed in the present account.

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

Morphology General Habit

Annual or perennial

Morphology Culms

Culms scapose

Morphology Leaves

Leaves often distichous, ligulate or eligulate

Morphology Reproductive morphology Inflorescences Bracts

Involucral bracts inconspicuous, often erect

Morphology Reproductive morphology Inflorescences

Inflorescence a solitary spikelet or one sessile and 1-several stalked spikelets with main bract filiform to leafy, usually less than 1 cm long

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets dark brown to almost black, broadly ovoid with many spirally arranged ovate or oblong glumes which have an indistinct midrib and are persistent on the rachilla after the nutlets have fallen

Morphology Reproductive morphology Flowers Gynoecium Style

Style 2-branched

Morphology Reproductive morphology Fruits

Nutlets smooth without persistent style-base.

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

Morphology General Habit

Delicate annual herbs of temporary wet areas, or perennials of more permanent wetland grassland, tufted or rhizomatous

Morphology Leaves

Leaves often short in relation to culm length, blade ± enrolled, sometimes ending in a sharp point, spiral or distichous, ligulate (most perennials) or eligulate (all annuals); long woolly hairs are present at orifice of leaf sheaths in most species

Morphology Culms

Culms and leaves glabrous, with narrow, longitudinal markings formed by silica bodies

Morphology Reproductive morphology Inflorescences

Inflorescence terminal or ± pseudolateral, (compound) anthelate, or capitate, or reduced to 1 or a few spikelets subtended by 1 or more primary bracts

Morphology Reproductive morphology Inflorescences Bracts

Bracts often stiffly erect, not sheathing

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets (cylindrical-) ovoid or spherical-Glumes spiral, densely imbricate, reddish-brown to blackish, each subtending a bisexual flower

Morphology General

Bristles absent

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 1–3

Morphology Reproductive morphology Flowers Gynoecium Style

Style branches 2 or 3, style base not distinct, not thickened and mostly deciduous

Morphology Reproductive morphology Fruits

Nutlet obovate, dorsiventrally lenticular or faintly trigonous (N. equitans), surface smooth, often shining black, rarely brownish to greyish.

Distribution

A genus of 8 species from grasslands in tropical Sudano-Zambesian Africa, 4 species in the Flora area.