叉花草 cha hua cao

Ruellia hamiltoniana Steudel, Nomencl. Bot., ed. 2, 2: 481. 1841, based on Goldfussia colorata Nees in Wallich, Pl. Asiat. Rar. 3: 89. 1832, not Ruellia colorata Blume (1826), nor Vellozo (1829); Diflugossa colorata (Nees) Bremekamp; Strobilanthes colorata (Nees) T. Anderson (1867), not Nees (1837).

Shrubs 0.5-1.5 m tall, much branched, anisophyllous. Stems 4-angled, sulcate, glabrous. Leaves petiolate or apical ones sessile or subsessile; petiole (0-)0.8-5(-8) cm, glabrous; leaf blade lanceolate to ovate, smaller pair at least 2/3 size of larger one, 5-19 × 2-8.5 cm, glabrous, densely covered with linear cystoliths, secondary veins 4-7 on each side of midvein, base oblique to rarely slightly oblique and attenuate or on very large leaves subcordate, margin serrulate, apex acuminate. Inflorescences axillary or terminal, panicles, to 30 cm, much branched; rachis angled at ca. 60°, glabrous or rarely pubescent, gland-tipped in fruit; bracts green, broadly obovate, 3-5 × ca. 2 mm, concave, caducous, glabrous, becoming gland-tipped in fruit, margin entire, apex retuse; bracteoles green, oblanceolate to narrowly elliptic, 3-4 × ca. 1 mm, concave, caducous, glabrous, margin entire, apex retuse. Flowers solitary on each node, distant on rachis. Pedicel 1.5-5 mm, glabrous. Calyx 8-10 mm, accrescent to ca. 1.3 cm in fruit, glabrous, sometimes apically gland-tipped pubescent, becoming densely gland-tipped in fruit, 5-lobed almost to base; lobes narrowly elliptic with one longer than others, apex acute to sometimes retuse. Corolla white, lilac, or (in cultivated forms) deep pink with a white tube, 3.5-4 cm, subventricose, outside glabrous, inside glabrous except for trichomes retaining style; tube basally cylindric and ca. 2 mm wide for ca. 1.3 cm then slightly ventricose and gradually widened to 1.4-1.8 cm at mouth; lobes ovate, 4-5 × ca. 6 mm, apex rounded to retuse. Stamens 4, included; filaments glabrous; shorter filament pair ca. 1 mm, equal; longer filament pair 7-9 mm, unequal, erect; anther thecae white, spherical, ca. 1.2 mm in diam., partially recurved; pollen type 3. Ovary ca. 2.5 mm, glabrous; style ca. 3.8 cm, sparsely pubescent. Capsule green then dark purple, fusiform, 1-1.5 cm, glabrous or with gland-tipped trichomes, 4-seeded. Seeds ovate in outline, ca. 3 × 2 mm, with long trichomes; areola small. Fl. Dec-Jan.

Forests on mountain slopes; 800-2000 m. Xizang (Cona) [Bhutan, India, Myanmar, Nepal].

Strobilanthes hamiltoniana is an ornamental plant. It is widely cultivated in tropical countries and in conservatories in temperate climates. The species is sometimes naturalized, occasionally becoming an invasive weed as on the island of Réunion. Cultivated plants and plants of cultivated origin seem always to be glabrous, pink-flowered, and sterile with dispersal being by cuttings or shoots broken off by grazing animals.

"Goldfussia tengyuehensis" (C. Y. Wu, Index Fl. Yunnan. 2: 1675. 1984) belongs here but was not validly published.