Pycreus 扁莎屬
作者
KOYAMA, Tetsuo, KUOH, Chang-Sheng & LEONG, Wai-Chao
型態特徵
Perennial or annual herbs, grass-like or rush-like, rarely with elongated woody caudices. Culms generally trigonous and solid. Leaves radical and/or cauline; blade linear or lanceolate-elliptic, sheathing at base, occasionally reduced to nearly bladeless sheaths; ligules present or absent; abaxial side of leaf sheaths sometimes projected beyond sheath orifice forming a tongue-like appendage (contraligule). Inflorescences various, mostly corymbose, paniculate, spicate, racemose or heads, subtended by leafy bracts, bearing 1 to numerous spikelets. Spikelets with few to many glumes; glumes imbricate or 2-ranked on a simple axis (rachilla); all or some glumes bearing an axillary flower or at times a bisexual cymule in axil, or rarely rachilla determinate with a single terminal pistillate flower and spikelet bearing 0-few small staminate partial spikelets in axils of some glumes. Flowers hermaphroditic or unisexual, without perianth or perianth of 3-many bristles or scaly segments. Stamens generally 1-3. Pistil bi- or tri-carpellate; styles 2- or 3-(rarely to 8-) fid at apex; ovary unilocular, with a single anatropous ovule; fruit an achene.
屬
A family of more than 5,000 species in 70-120 genera, distributed throughout the world under all ecological conditions, with the highest generic concentration in tropical South America. The family is divided into five tribes: Cariceae, Cypereae, Mapanieae, Rhynchosporeae and Sclerieae.
參考文獻
Pycreus 扁莎屬
作者
KOYAMA, Tetsuo, KUOH, Chang-Sheng & LEONG, Wai-Chao
型態特徵
Spikelets with few to many glumes distichously disposed on a continuous simple axis (rachilla), laterally flattened. Glumes all alike, bearing a bisexual flower in axil. Flowers a digynous pistil, without hypogynous bristles; stamen 1-3. Achenes bilaterally flattened, lenticular, with one of angles facing rachilla, sides puncticulate or undulate; style not jointed at base; stigmas 2.
Vegetative characters as in Cyperus.
Type species. Pycreus polystachyos (Rottb.) P. Beauv. About 70 species in temperate, subtropical and tropical regions of all the world, with high concentration of species in Africa.
