Gahnia 黑莎草屬
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
Gahnia 黑莎草屬
作者
KOYAMA, Tetsuo, KUOH, Chang-Sheng & LEONG, Wai-Chao
型態特徵
Spikelet with several glumes, 1- or 2-flowered, when 2-flowered upper flower bisexual and fruitbearing, lower flower staminate; glumes spirally imbricated on a continuous rachilla, chartaceous, usually dark brown, lower 3 to 8 (occasionally more) lanceolate, acute-tipped, 1-costate, empty, upper 2 or 3 smaller than remaining glumes, obtuse, thin at anthesis, becoming thick in fruit tightly enveloping fruit, uppermost glume bearing a bisexual flower. Perianth none (very rarely represented as hypogynous bristles in extra Taiwan species). Stamens 3-6; filaments often stretching after anthesis and persistent below achene. Achenes ellipsoid or ovoid, trigonous or subterete, bony exocarp shiny and hard; style slender, base not thickened; stigmas 3.
Type species. Gahnia schoenoides Forst. About 30 species distributed in the pacific Islands, Australia, New Zealand, Malesia, Indochina and southeastern China, the Ryukyus and Bonin Islands. A single species in Taiwan.
