Ranunculus trichophyllus Chaix in Villars, Hist. Pl. Dauph. 1: 335. 1786. R. aquatilis L. var. trichophyllus (Chaix) Hook. f. & Thomson in Fl. Brit. India 1: 16. 1872.

Herbs, aquatic, perennial. Leaves all submerged, divided into many capillary segments, 2 - 3 cm long, dark green; laminate leaves absent; petioles ca 5 mm long, sheathed at base with an auricle of the same length. Flowers white, 1.2 - 1.5 cm across; pedicels solitary in leaf axils, 2.5 - 3.5 cm long. Sepals elliptic, ca 3.5 mm long, reflexed. Petals obovate, 5 - 6 x 2 - 2.5 mm, white, yellow near the base; nectar-pit lunate. Achenes 25 - 30, obovoid, ca 1.5 mm long, strongly ribbed, hispid; fruiting peduncles shorter than leaves, distinctly curved.

Fl. & Fr. May - Aug.

Distrib. India: Himalayas, temperate and subalpine regions, in ponds and slow-flowing streams, 3500 - 4500 m. Jammu & Kashmir, Himachal Pradesh, Uttar Pradesh and Punjab.

China (Tibet), Nepal, Pakistan, Eurasia, Africa and N. America.