大叶细辛 da ye xi xin

Herbs. Rhizomes horizontal, 2-3 mm in diam., internodes less than 1 cm. Leaves solitary; petiole 10-23 cm, glabrous; leaf blade adaxially dull green, rarely with white blotches, narrowly to broadly ovate, or nearly hastate, 6-13 × 7-15 cm, abaxial surface glabrescent, adaxial surface pubescent along veins and margin, base cordate, lateral lobes 3-7 × 3.5-6 cm, apex acute; cataphylls ovate, 1-1.8 × 0.8-1 cm. Peduncle ascending to recurved, 1-5 cm. Calyx dark purple, campanulate-rotate, 3-4 × 4-6 cm; sepals connate beyond attachment to ovary, abaxially glabrous; tube campanulate, ca. 2.5 × 1.5-2 cm, middle portion abruptly swollen forming a robust girdle-like ring near middle abaxially lacking ridges, slightly constricted at throat, adaxially longitudinally ribbed, orifice ring absent or corrugate and not contiguous; lobes broadly ovate, 2-4 × 2-3 cm, basal 1/2 with transversely papillate-corrugate rows, base with white semicircular pulvinate area. Stamens 12; filaments much shorter than anthers; connectives slightly extended beyond anthers, obtuse. Ovary half-inferior. Styles free, apex 2-forked; stigmas lateral. Fl. Apr-May.

* Forests, in humus; 600-800 m. Hubei, Sichuan.