1. Catabrosa capusii Franchet, Ann. Sci. Nat., Bot., sér. 6. 18: 272. 1884.
长颖沿沟草 chang ying yan gou cao
Catabrosa aquatica subsp. capusii (Franchet) Tzvelev.
Perennial, rhizomatous. Culms decumbent at base, up to 30(–60) cm tall. Leaf sheaths closed up to middle, loose, longer than internodes; leaf blades flat, soft, 3–8 cm × 2–4 mm, apex acute; ligule ca. 2 mm, obtuse. Panicle narrow, contracted, almost spikelike, interrupted below, 2–12 × 0.8–1.5 cm; branches less than 5 cm, adpressed or suberect, compactly spiculate to base. Spikelets with (1–)2 florets, 3–4 mm; glumes oblong, obscurely 1–3-veined, apex obtuse or erose, lower glume 0.5–2 mm, upper glume 1.5–2.3 mm; lemma 2–2.7 mm, brown flushed purple, smooth, apex truncate, denticulate. Anthers 1–1.5 mm. Fl. Jun–Aug.
Marshy ground and water meadows on high mountains; 3700–4900 m. Nei Mongol, Xizang [Kyrgyzstan, Tajikistan, Uzbekistan; SW Asia (N Iran, N Iraq, E Turkey)].
Young panicles of Catabrosa aquatica can resemble the narrow panicle of this species.