小水毛茛 xiao shui mao gen

Ranunculus aquatilis Linnaeus var. eradicatus Laestadius, Nova Acta Regiae Soc. Sci. Upsal. 11: 242. 1839; Batrachium trichophyllum (Chaix ex Villars) Bosch var. paucistamineum (Tausch) Handel-Mazzetti; B. trichophyllum var. paucistamineum f. terrestre (Grenier & Godron) Handel-Mazzetti; R. paucistamineus Tausch; R. trichophyllus Chaix ex Villars var. terrestris Grenier & Godron.

Herbs perennial, small, terrestrial or in shallow water. Stems 1.5--8(--14) cm, simple or branched, glabrous. Petiole 5--16 mm, glabrous, sometimes broad sheath abaxially sparsely strigose; leaf blade flabellate in outline, 4--13 × 7--25 mm, glabrous, 3-sect; segment 2 or 3(or 4) × sect, ultimate lobules filiform, ± rigid, remaining divaricate out of water. Flower 0.6--1.2 cm in diam. Pedicel 1--2 cm, glabrous. Receptacle conical in flower and fruit, puberulent. Sepals 5, elliptic, 2--4 mm, glabrous. Petals 5, white with yellow base, obovate or narrowly obovate, 2.5--7.2 × 1.5--4 mm, apex rounded. Stamens 4--12; anthers oblong, 0.5--0.9 mm. Aggregate fruit broadly ovoid, ca. 2.5 × 4 mm; achenes obliquely narrowly obovoid, 1.2--1.5 × 0.8--1 mm, glabrous or sparsely puberulent, with ca. 6 transverse wrinkles. Persistent style ca. 0.2 mm. Fl. May--Sep.

Ponds, shallow water, swamps; 500--3900 m. N Heilongjiang, N Nei Mongol, W Sichuan, N Xinjiang, SE Xizang, NW Yunnan (Lijiang Naxi Zu Zizhixian) [Kazakhstan, Russia (Siberia); Europe, North America].