7. Poaceae Tribe STIPEAE
针茅族 zhen mao zu
Authors: Zhen-lan Wu & Sylvia M. Phillips
Perennials, usually forming tussocks. Leaf blades linear to filiform, often convolute or folded; ligule membranous, margin often ciliolate. Inflorescence an open or contracted panicle, sometimes spikelike, spikelets all alike. Spikelets with 1 floret (to 3 in Duthiea), terete or laterally compressed, disarticulating above glumes; rachilla extension usually absent (present in Stephanachne, Sinochasea, and Duthiea); glumes equaling or longer than floret, persistent, hyaline to membranous, 1–7-veined; floret callus obtuse to pungent; lemma rounded on back, membranous to leathery, firmer than glumes, often indurated at maturity, 3–9-veined, often enclosing palea, apex entire or 2-toothed, awned from apex or between teeth; awn straight or geniculate, glabrous, pubescent or plumose; palea subequal to lemma, hyaline to membranous, usually 2-veined (5–7-veined in Psammochloa) but not keeled, apex usually acute. Lodicules 2 or 3. Stamens mostly 3 (1 in Stephanachne monandra), anthers sometimes bearded with apical tuft of short hairs. Stigmas 2 or 3. Caryopsis fusiform, tightly enclosed by lemma and palea; hilum linear; embryo short.
Between nine and 17 genera: temperate and warm-temperate regions; ten genera (one endemic) and 67 species (17 endemic) in China.
The number of genera that should be recognized in Stipeae is still controversial. Sometimes a broad view is taken of Stipa, but in Asia it has usually been broken into segregate taxa. This traditional treatment is followed here, with a few exceptions, to avoid the creation of many new combinations while the taxonomy is still unsettled.
Additionally, the first four small genera are of uncertain tribal placement. These are little known, undercollected grasses from the Himalayas and W China. They are sometimes placed in Aveneae, but on balance show more Stipoid characteristics, including multiveined glumes, an unkeeled palea, often 3 lodicules, and a linear hilum.
Lemma measurements refer to the lemma body and the callus together.