细芒羊茅 xi mang yang mao

Festuca undata Stapf var. aristata Stapf.

Plant tufted; shoots extravaginal. Culms 20–70 cm tall, nodes 2, dark brown. Leaf sheaths smooth or basal sheaths pubescent; auricles present as erect swellings; leaf blades conduplicate, flaccid, 3–10 cm × 0.8–1 mm, veins 7–9; adaxial to abaxial sclerenchyma strands absent, abaxial sclerenchyma in narrow discrete strands; ligule 0.3–0.5 mm, margin ciliate. Panicle loose, open, 6–23 cm; branches 3–6 cm, filiform, scabrid, 1(–2) at lowest node. Spikelets 6–8.5(–9.5) mm, greenish or purplish; florets 3–4(–7); glumes smooth, margins broadly membranous; lower glume narrowly lanceolate, 2–2.5(–3.8) mm; upper glume lanceolate, 3–4.5(–6.5) mm; rachilla internodes 1–1.5 mm; lemmas 5–6.5 mm, smooth, acuminate; awns (3–)5–8 mm; palea keels scabrid. Anthers 1–1.8 mm. Ovary apex glabrous when young, later sparsely hairy. Fl. and fr. Jul–Sep.

Grassy mountainsides, chalky meadows, forest margins; 3000–3200 m. Sichuan, Xizang, Yunnan (E Lijiang mountains) [Bhutan, India (Darjeeling, Sikkim), Nepal].

Festuca undata Stapf, from India (Sikkim), differs by its extravaginal shoots, shorter awns 0.7–1.4 mm, and smaller anthers 0.5–0.7 mm.