70. Colpodium Trinius, Fund. Agrost. 119. 1822.
小沿沟草属 xiao yan gou cao shu
Authors: Zhen-lan Wu & Sylvia M. Phillips
Catabrosella (Tzvelev) Tzvelev; Colpodium subg. Catabrosella Tzvelev; Colpodium subg. Paracolpodium Tzvelev; Paracol-podium (Tzvelev) Tzvelev.
Small perennials, tufted or rhizomatous. Leaf sheaths with partially connate margins, rarely split to base; leaf blades linear, flat or folded, apex hooded; ligule membranous. Inflorescence an open or contracted panicle or reduced to a raceme. Spikelets with 1–4 florets, glistening; rachilla disarticulating below each floret, extension above floret(s) short or absent; glumes unequal to subequal, upper glume 1/2 as long as to equaling or exceeding florets, lower glume 1-veined, upper glume 3-veined; lemmas ovate or oblong, thinly membranous becoming hyaline at apex, keeled, 3–5-veined below middle, intermediate veins often obscure or absent, veinless toward apex, glabrous or hairy on lower veins or back, apex obtuse to acute; palea about equal to lemma, keels smooth, glabrous or often hairy. Stamens 2 or 3. Caryopsis free or lemma and palea partially adherent; hilum elliptic to oblong. x = 2, 4, 5, 6, 7, 9.
Twenty-two species: Turkey eastward through the Caucasus to the Himalayas and E Siberia, also on a few mountains in Africa; five species in China.
Colpodium species usually occur on high mountains. They often resemble Poa morphologically, but can be distinguished by the thinner lemmas with veinless tips and smooth palea keels. Species with long glumes, a single floret, and 3-veined lemmas are not easily recognizable as members of tribe Poeae.