2. Biophytum sensitivum (Linnaeus) Candolle, Prodr. 1: 690. 1824.
感应草 gan ying cao
Oxalis sensitiva Linnaeus, Sp. Pl. 1: 434. 1753; Biophytum cumingianum (Turczaninow) Edgeworth; O. cumingiana Turczaninow; O. metziana Miquel ex Edgeworth & J. D. Hooker.
Annuals 5-25 cm tall, base woody. Stem simple, slender to robust, hispid especially apically. Leaves 3-13 cm; rachis slender, moderately hispid; leaflets 6-14 pairs; leaflet blades oblong to obovate-oblong, 3-15 × 2-7 mm, usually glabrous, occasionally sparsely covered with trichomes, base almost symmetric. Umbels several flowered; peduncle 2-7 cm, subequal to leaf length; bracts several, lanceolate, ca. 2 mm, densely crowded at apex of peduncle, cluster ca. 3 mm. Pedicel ca. 1 mm at anthesis but to 3 mm in fruit. Sepals 5-6 mm, with glandular septate trichomes. Petals yellow, longer than sepals. Capsule ellipsoid-obovoid, 4-5 × 3-4 mm, pubescent. Fl. and fr. Jul-Dec.
Roadsides, mountain slopes, forest floors; 100-700 m. SW Guangxi, ?Guizhou, Hainan, Taiwan, Yunnan [India, Indonesia, Malaysia, Nepal, Philippines, Sri Lanka, Thailand, Vietnam; tropical Africa].
This species is used medicinally.
Unvouchered reports of Biophytum sensitivum from Guizhou (L. Yang, Fl. Guizhou. 6: 27. 1989) need confirmation.
This species is similar to Biophytum reinwardtii (Zuccarini) Klotzsch of Bhutan, India (W Himalaya), Malaysia, Myanmar, Nepal, and Thailand, which differs in the longer pedicels (5-7 mm) and capsules, which are longer than sepals.