3. Poa subg. Pseudopoa (K. Koch) Stapf in J. D. Hooker, Fl. Brit. India. 7: 337. 1896 [“1897”].
假早熟禾亚属 jia zao shu he ya shu
Authors: Guanghua Zhu, Liang Liu & Robert J. Soreng
Festuca [unranked] Pseudopoa K. Koch, Linnaea 21: 409. 1848; Eremopoa Roshevitz.
Slender annuals or ephemerals, shoots intravaginal. Culms erect. Inflorescence an open panicle; branches whorled, scabrid angled. Spikelets slightly compressed, elliptic, florets (1 or)2 to many, distant or only slightly overlapping; rachilla filiform, scabrid; glumes unequal, shorter than floret, lower glume 1-veined, upper glume 3-veined; lemmas lanceolate to narrowly oblong in side view, rounded on back or slightly keeled at base, herbaceous, 5-veined, apex obtuse to acuminate or mucronate, glabrous or keel and marginal veins pilulose to short villous, intermediate veins faint; palea equaling or shorter than lemma, keels scabrid; callus glabrous. Stamens (2–)3. Caryopsis partly adherent to lemma and palea, faintly grooved; hilum oval.
About five species: NE Africa, C and SW Asia, Europe; one species in China.
Species of Poa subg. Pseudopoa have a delicate, annual habit and whorled, scabrid-angled panicle branches. The subgenus comprises two widespread, variable species, which are sometimes subdivided, and a few local species in SW Asia. Since 1934, they have usually been recognized as a separate genus, Eremopoa, but molecular data place them in the middle of Poa. Poa persica Trinius occurs from Turkey to Afghanistan and Pakistan, but has not yet been found in China. It can be recognized by its lemmas with broad, membranous margins and obliquely truncate tips in side view, and by having anthers 1.4–2.5 mm.
