紫花丹 zi hua dan

Plumbago rosea Linnaeus; Thela coccinea Loureiro.

Herb, perennial, 0.5--2 m tall, evergreen. Stems pliable, often lianous, simple or branched from base. Petiole base without auricles; leaf blade narrowly ovate to elliptic-ovate, (3--)7--9.5(--13) X (0.8--)3--4(--6) cm, papery, base rounded to obtuse, apex acute. Inflorescences spicate-racemose, (20--)35--90-flowered; peduncle 1--3 cm, not glandular; rachis (8--)10--40(--50) cm, not glandular; bracts ovate, 2--3 X 1.5--2 mm, apex acuminate; bractlets obovate-elliptical to ovate, 2--2.5 X 1.5--2 mm, apex acute. Calyx 7.5--9.5 mm, glandular almost throughout, tube ca. 2 mm in diam. at middle. Corolla purple to dark red, tube 2--2.5 cm, limb ca. 2 cm in diam.; lobes obovate, ca. 12 X 7 mm, apex rounded and mucronate. Anthers blue, 1.5--2 mm. Ovary ellipsoid-ovoid, indistinctly angular. Heterostylous; style basally pilose; short-styled form with style arms only partly exserted, stigmatic glands without enlarged apex; long-styled form with style arms completely exserted from corolla throat, stigmatic glands capitate. Fruit not seen. Fl. Nov-Apr. 2n = 14.

Wet grasslands; 0--300 m. Hainan, SE Yunnan [Old World tropics].

Medicinal and ornamental.