石龙尾 shi long wei

Hottonia sessiliflora Vahl, Symb. Bot. 2: 35. 1791; Ambulia sessiliflora (Vahl) Baillon ex Wettstein; L. taoyuanensis Yang & Yen.

Perennials, amphibious. Submerged stems slender, long, glabrous or subglabrous. Aerial stems 6-40 cm, simple or sparsely branched, eglandular hairy, rarely subglabrous. Submerged leaves 0.5-3.5 cm, multiparted; segments flattened or capillary. Aerial leaves whorled; leaf blade elliptic-lanceolate, 5-18 X 3-4 mm, glabrous, densely glandular punctate, margin crenate to lobed; veins 1-3. Flowers sessile or rarely with a pedicel to 1.5 mm, solitary in axils of submerged and aerial leaves. Bracteoles absent or rarely present and to 1.5 mm. Calyx 4-6 mm, eglandular hairy, without raised veins in fruit; lobes 2-4 mm, ovate, apex narrowly acuminate. Corolla purple-blue to reddish, 6-10 mm. Capsule compressed, subglobose. Fl. and fr. Jul-Jan.

Ponds, swamps, rice fields, wet places along streams; below 1900 m. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Henan, Hunan, Jiangsu, Jiangxi, Liaoning, Sichuan, Taiwan, Yunnan, Zhejiang [Bhutan, India, Indonesia (Java), Japan, Korea, Malaysia, Myanmar, Nepal, Sikkim, Sri Lanka, Vietnam].

Limnophila trichophyllaLimnophilatrichophylla (Komarov) Komarov has been reported from NE China and Taiwan. From illustrations and the original description, the species is similar to L. sessiliflora, but we have not seen any specimens. The same is true for the recently described L. taoyuanensis (Bot. Bull. Acad. Sinica 38: 285-295. 1997).

Bentham (in N. Wallich, Numer. List 137. 1831) seems to have been the first to correct Blume's spelling sessiflora to sessiliflora, and later works have generally accepted the corrected epithet. Some works treat Hottonia sessiliflora Vahl (in Symb. Bot. 2:36. 1791) as the basionym, but no homotypy has been established between Blume's and Vahl's names.