Bidens bipinnata (PROSEA)
- Protologue: Sp. pl. 2: 832 (1753).
Bidens pilosa L. var. bipinnata (L.) Hook.f. (1881).
- Spanish needles (En). Bident bipenné (Fr)
- Vietnam: vạn thọ tây, song nha kép.
Native to North America and eastern Asia; introduced and occurring as a weed in southern Europe, Central and South America, Africa, Australia and elsewhere in Asia. In Malesia, only known from the Philippines.
The warmed juice of the leaves is used to treat conjunctivitis, against earache and as a styptic on wounds. The roots and seeds are used as an emmenagogue, expectorant, stimulant and antispasmodic, and also to treat asthma. In China, B. bipinnata is used to treat stings of insects, snake bites, and unhealthy granulations of wounds. In Taiwan, a decoction of the entire plant is used as an antidiarrhetic.
An annual, erect herb up to 1.5(-2.5) m tall, stem 4-angular, glabrous or minutely hispid in the upper part; leaves opposite, occasionally alternate towards the apex, bipinnatisect with the lower segment often 2-3-cleft or pinnatifid, 11-20 cm long, the segments ovate to deltoid or the terminal one lanceolate, margin crenate-serrate, petiolate; capitula in lax paniculate cymes, radiate, 4-6 mm broad, outer involucral bracts 7-10, 3-5 mm × 0.5 mm, shorter than the inner ones; ray flowers 3-5, corolla 5-6 mm long, yellow, disk flowers with yellow, 4-5 mm long corolla; achene linear-fusiform, 4-angular, 7-18 mm long, with (2-)4 retrorsely barbed bristles of 2-4 mm. B. bipinnata is found on roadsides, wasteland, and field margins, up to 1400 m altitude; in the Philippines it has been found on dry slopes at 1300 m.
289, 458, 852, 935, 938, 1126, 1329.
D.S. Alonzo & J.W. Hildebrand