紫背细辛 zi bei xi xin

Herbs. Rhizomes vertical, 2-3 mm in diam., internodes less than 1 cm. Leaves solitary; petiole 5-15 cm, glabrescent; leaf blade abaxially uniformly purple-red or greenish, adaxially with or without white blotches, elliptic-oblong to broadly ovate, rarely nearly hastate, 6-10 × 5-7 cm, abaxial surface glabrescent, adaxial surface sparsely pubescent along veins and margin, base auriculate to cordate, apex acute or obtuse; cataphylls broadly ovate, 1-2 cm × 8-10 mm. Peduncle ascending, 3-6 cm. Calyx purple-green, rotate-urceolate, 1.5-2 × 2-2.5 cm; sepals connate beyond attachment to ovary, abaxially glabrous; tube urceolate, 1-1.2 × 1.1-1.4 cm, strongly constricted at throat, adaxially tessellate, orifice ring ca. 1 mm wide; lobes broadly triangular-ovate, ca. 0.8 × 1 cm, base densely papillate in a triangular pattern. Stamens 12; filaments much shorter than anthers; connectives slightly extended beyond anthers, acute to obtuse. Ovary nearly superior. Styles free, apex 2-forked; stigmas lateral. Fl. Apr-May.

* Forests, thickets, moist shady areas. Sichuan.

This species contains carcinogenic substances.