Fimbristylis Vahl

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 scapose or subscapose

Morphology Leaves

Leaves sometimes reduced to a sheath only; ligule sometimes a fringe of hairs

Morphology Reproductive morphology Inflorescences

Inflorescence usually compound of many spikelets, less often reduced to a single spikelet

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets with spirally arranged or less often distichous glumes, the lower 1–2 usually empty, the next bisexual and the uppermost male or sterile

Morphology Reproductive morphology Flowers Perianth

Perianth segments absent

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 1–3

Morphology Reproductive morphology Fruits

Nutlets smooth, tuberculate or longitudinally ribbed, not transversely wrinkled. Fruit trigonous when style is 3-fid, and lenticular when 2-fid

Morphology Reproductive morphology Flowers Gynoecium Style

Stylebase widened, falling with rest of style Styles 2–3-fid, often flattened with fimbriate margins when 2-fid, the base distinct and thickened

M. Thulin et al. Flora of Somalia, Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit

Tussocky annual or perennial herbs, or stems more distant from rhizomes or stolons

Morphology Stem

Stems terete, angular or flattened, glabrous or scabrid

Morphology Leaves

Leaves mostly basal; sheaths glabrous or short-hairy, without long flexuose whitish hairs at opening; blades usually well developed, flat, linear, to c. 40 cm long and most often 1–3 mm wide, glabrous or short-hairy

Morphology Reproductive morphology Inflorescences

Inflorescence a lax anthela of 1 sessile spikelet and 1–numerous stalked spikelets or new groups of sessile and stalked spikelets, more rarely spikelets congested, or inflorescence a terminal spikelet only; involucral bracts usually leafy and spreading, shorter or longer than the inflorescence

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets ovate to elongate, with numerous bisexual flowers subtended by spirally arranged glumes

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes ovate to lanceolate or almost orbicular, glabrous or short-hairy, sometimes with longer hairs on margin; midrib ending below apex or excurrent in a short or long mucro or awn

Morphology Reproductive morphology Flowers Perianth

Perianth absent

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 1–3

Morphology Reproductive morphology Flowers Gynoecium Style

Style often strongly flattened and fimbriate, with 2 or 3 stigmas; base of style widened but falling with the rest of the style, very rarely with slender processes descending from the style-base over the nutlet

Morphology Reproductive morphology Fruits

Nutlet orbicular or obovate to almost cylindrical, triangular or biconvex, smooth, tuberculate or reticulate with hexagonal or linear surface cells that are never longer than wide when seen from base towards apex.

Distribution

About 320 species in all tropical and subtropical parts of the world, but especially numerous in Asia and Australia.

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 and annual, occasionally biennial herbs, densely to sparsely tufted; rhizome sympodial, woody, or hardly developed

Morphology Leaves

Leaves variable, sheaths usually closely enclosing culms, splitting with age; mouth truncate or sloping, glabrous, or ciliate; ligule 0 or a line of short hairs; blades well-developed or obsolete (both can be found in same population or on same plant, F. complanata), width variable, occasionally filiform, apex often asymmetric. Culms scapose, terete or ridged by 2–6 angles, variously pubescent to glabrous

Morphology Reproductive morphology Inflorescences

Inflorescences terminal, variable on individual plants, anthelate of c. 1–200 spikelet(s) in 3, 2, 1 or 0 branching systems

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets compact, mostly cylindric, many-flowered, basal glumes early deciduous

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes basal, 1–2, sterile, remainder (except most apical) subtending one bisexual floret

Morphology Reproductive morphology Flowers Perianth

Perianth 0

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 3, 2 or 1

Morphology Reproductive morphology Flowers Gynoecium Style

Style 2(3)-angled, ribbon-like or filiform, villous, ciliate, glabrescent or glabrous, base thickened, distinct, occasionally of style width

Morphology Reproductive morphology Fruits

Nutlet biconvex or trigonous, obovate, ovate-orbicular in outline; gynophore sometimes present; surface usually longitudinally ridged, trabeculate, occasionally smooth, seldom tuberculate; epidermal cells subquadrate or transversely elongate, generally lacking silica deposits.

Distribution

A large genus of c. 300 species, cosmopolitan with its maximum diversity in Malaysia.

Recognition

Species are not easily identified by a few simple characters. Several sub-genera have been established, with some having been given generic status.