四川草沙蚕 si chuan cao sha can

Culms 15–30 cm tall. Basal leaf sheaths papery; leaf blades inrolled or flat, 1–10 × 0.1–0.2 cm, adaxial surface scabrid, sometimes pilose with long scattered hairs, abaxial surface glabrous. Racemes 5–13 cm, spikelets imbricate by 1/3–1/2 their length. Spikelets 5–13 mm, olive green; florets 5–10, approximate, rachilla partially visible; lower glume lanceolate, nearly symmetrical, 2.1–2.7 mm, acuminate-mucronate; upper glume lanceolate-oblong, 3.5–4.3 mm, 1–3-veined and thickened along midline, margins broad, scarious, apex subacute, mucronate; lemmas oblong-ovate, 2.8–3 mm to sinus, 2-dentate, central awn slightly shorter to slightly longer than its lemma, 1.8–3.3 mm, erect, teeth rounded to truncate, lateral veins extended into 0.1–0.5 mm mucros; palea keels wingless, ciliolate. Anthers 3, 1.2–1.3 mm. Fl. and fr. Jun–Aug.

* Mountain slopes, dry valleys; 1600–3200 m. Sichuan.

Tripogon sichuanicus has been misidentified as either T. filiformis or the Indian species T. bromoides Roth ex Roemer & Schultes. It is clearly separated from T. filiformis by its short, blunt lemma teeth and by the presence of 3 anthers. Tripogon bromoides differs in having a much broader raceme, 0.8–1.5 cm wide, with spikelets diverging at an angle from the rachis, a lower glume with a lateral lobe, prominent, acute lemma teeth, and longer lateral awns. Tripogon sichuanicus is actually much closer to T. chinensis, although that species has shorter awns and a more easterly distribution.