Whorl Grass

Catabrosa aquatica is a widespread, polymorphic species of aquatic and marshy habitats, and extreme forms are sometimes accorded separate status, either at specific or infraspecific rank.

This species provides good forage.

An aquatic grass with sweet stems and succulent foliage eagerly sought by cattle. Smaller plants with panicles about 6 cm long and purple spikelets have been separated as Catahrosa sikkimensis, but such variants occur sporadically throughout the range of Catahrosa aquatica and are of little taxonomic consequence. Another variant, even less well-marked, has shorter panicle branches (up to 5 cm) and smaller lemmas (1.5-1.7 mm long). It is sometimes separated as var. angusta.

Perennial, rhizomatous; rhizome stout, creeping. Culms erect, succulent, 20–70 cm tall, unbranched. Leaf sheaths closed up to middle, upper shorter than internodes; leaf blades equally wide throughout, soft, 5–20 cm × 2–8 mm, apex boat-shaped; ligule 2–5 mm, obtuse. Panicle open or loosely contracted at anthesis, ovate to oblong in outline, 10–30 × 4–12 cm; branches whorled, slender, usually obliquely ascending, up to 10 cm, often bare of spikelets in lower part. Spikelets with (1–)2(–3) florets, 2–4(–5.8) mm; glumes obtuse or subtruncate; lower glume ovate to suborbicular, 0.5–1.2(–2) mm; upper glume broadly elliptic, 1–2(–3) mm; lemma 1.5–3 mm, green becoming brown at maturity, usually glabrous, apex truncate. Anthers 1–2 mm. Fl. and fr. Apr–Aug. 2n = 20.

Stoloniferous perennial; cuhms 5-70 cm high, erect or geniculately ascending, slender to somewhat stout, succulent, smooth. Leaf-blades 4-20 cm long, 2-10 mm wide, rather thin. Panicle ovate to oblong, 5-30 cm long, 2.5-10 cm wide, the branches in half whorls of 3-5, successive whorls alternating. Spikelets 3-5 mm long, breaking up at maturity between the lemmas, green, yellow or brown, often variegated with purple; glumes obovate, blunt, the lower 1-1.5 mm long, the upper 1.5-2.5 mm long; lemma (1.5-)2.5-3.5 mm long, smooth or with minute hairs on the nerves.

Gansu, Guizhou, Hebei, Hubei, Nei Mongol, Qinghai, Sichuan, Xinjiang, Xizang, Yunnan [Afghanistan, Kashmir, Kazakhstan, Kyrgyzstan, Mongolia, Pakistan, Russia, Tajikistan, Turkmenistan; SW Asia, Europe, North America].

Distribution: Pakistan (Baluchistan & Kashmir); throughout the range of the genus.

Slow-moving, shallow water of river and streamsides, muddy pond margins, ditches; 800–4000 m.