单叶淫羊藿 dan ye yin yang huo

Herbs, 30-55 cm tall. Rhizomes brown, stout, squamate at upper part. Leaves simple, basal and cauline; petiole of stem leaf 5-7 cm, glabrous; leaf blade adaxially green, ovate or broadly elliptic-ovate, 7-19 × 8-10 cm, papery, abaxially densely sericeous, veins conspicuously raised, adaxially glabrous, reticulate veins conspicuous, base deeply or shallowly cordate with lobes rounded, subequal, margin closely spinulose-subserrulate, apex acute. Flowering stem with 2 opposite leaves. Inflorescence a terminal panicle, 12-22 × 8-10 cm, usually 15-32-flowered; rachis glabrous. Pedicel 1-2.5 cm, puberulent. Flowers yellow. Sepals 8 in 2 whorls; outer sepals obovate, ca. 4 × 2 mm, apex obtuse; inner sepals ovate, ca. 6 × 4 mm, membranous, apex acute. Petals curved upward, reddish purple, horn-shaped, much longer than inner sepals, ca. 2 cm. Stamens 4, pale yellow, ca. 3 mm; filaments shorter than anthers; anthers valved. Pistil obliquely terete; style ca. 1 mm. Capsules obliquely terete, glabrous; style rostriform. Fl. Apr-May, fr. May-Jun.

● Slopes in valleys; ca. 1100 m. Guizhou.