Rhynchospora Vahl

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

Morphology General Habit

Annuals or perennials, rhizomatous or with a poorly developed rootsystem

Morphology Culms

Culms rounded to trigonous

Morphology Leaves

Leaves with sheaths closed; ligule 0, or very inconspicuous ( R gracillima)

Morphology Reproductive morphology Inflorescences Bracts

Involucral bracts leaf-like or short

Morphology Reproductive morphology Inflorescences

Inflorescence capitate, simple, corymbose or paniculate, then with clusters of spikelets on peduncles emerging from the axils of the leaves up the culm; clusters of spikelets often corymbose, few to many per cluster

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets sessile or pedicellate.

Morphology Reproductive morphology Inflorescences Bracts Glume

Lower 2–3 glumes empty (sterile) and small, the remainder gradually larger, the uppermost glume often empty Glumes spirally arranged or distichous, imbricate, few or many ( R candida).

Morphology Reproductive morphology Flowers

Flowers either all bisexual, the upper ones not maturing the nutlet, or lower 1–few bisexual and upper ones staminate, or unisexual with the lowest pistillate and upper one(s) staminate

Morphology Reproductive morphology Flowers Perianth

Perianth segments 0–6, bristle-like, upwardly scabrid

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 2–3.

Morphology Reproductive morphology Flowers Androecium Stamens Filaments

Filaments flattened

Morphology Reproductive morphology Fruits

Nutlets biconvex.

Morphology Reproductive morphology Flowers Gynoecium Style

Style base persistent, with or without pedicel. Style unbranched, slightly bifid or with 2 long branches

Note

250 species, especially in tropical South and Meso-America.

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, sometimes short-lived or annual herbs, tall or short, erect or tufted, sometimes geniculate rooting from lower culm nodes or rhizomatous

Morphology Culms

Culms strict or branching, noded or nodeless, internodes trigonous or irregularly ridged

Morphology Leaves

Leaves radical or radical and cauline; sheaths closed, ligule minute or 0

Morphology Reproductive morphology Inflorescences

Inflorescence compound, a fasciculate corymbose cyme or a solitary, capitate head

Morphology Reproductive morphology Inflorescences Bracts

Bracts leaf-like or reduced

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets with glumes spirally imbricate or distichous, few to many (R. candida); central florets bisexual, with reduction of lowest few to sterility and/or upper florets staminate (variable with species)

Morphology Reproductive morphology Flowers Perianth

Perianth of (2–3)6(7) rigid, scabrid bristles, sometimes reduced or lacking

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 3(2–1)

Morphology Reproductive morphology Flowers Gynoecium Style

Style branches 2, long, short (hardly visible), or 0; base persistent, epaulette-like over nutlet apex (variable in form with species)

Morphology Reproductive morphology Fruits

Nutlets biconvex, obovoid, elliptic or square; surface smooth to faintly to markedly transversely ridged, or glabrous and punctute, or partially or completely hairy.