Volume 13 > Part 2 > Year 2016 > Page 196 > Compositae (Asteraceae) > Bidens

1. Bidens bipinnata L.wfo-0000028784

Sp. Pl. 2: 832. 1753; Gagnep., Fl. Indo-Chine 3: 608. 1924; Kerr, Fl. Siam. 2(3): 280. 1936; Sherff, Publ. Field Mus. Nat. Hist., Bot. Ser. 16: 366. 1937; Chen & Hu, Fl. Reipubl. Popularis Sin. 75: 380. 1979; Kitam. & Gould in Hara, Chater & Williams, ed., Enum. Fl. Pl. Nepal 3: 15. 1982; H.Koyama, Acta Phytotax. Geobot. 36: 60. 1985; Y.S.Chen & D.J.N.Hind, Fl. China 20–21: 859. 2011.— Bidens pilosa var. bipinnata (L.) Hook.f., Fl. Brit. India 3: 309. 1881. Fig. 15.

Accepted Name : This is currently accepted.

Synonyms & Citations :

Description : Annual herb, 10–80 cm tall; stems erect from tap roots, slightly hairy in upper part. Leaves many, cauline; median leaves opposite, petiolate, blade broadly ovate in outline, 7–12 by 7–11 cm, bipinnately partite, both surfaces slightly hairy, terminal segment narrowly acuminate, few-toothed near base, lateral segments often 2 or 3, or pinnately cleft, petioles 3.5–5.0 cm long; upper leaves gradually smaller, alternate, pinnately partite. Inflorescence peduncles slender, ca 3.5 cm long. Capitula radiate, 6–10 mm diam. at flowering; involucres cupuliform, 4–5 by ca 3 mm; phyllaries 5–7, biseriate, herbaceous, pubescent, lanceolate, 3–4 mm long at flowering, to 5 mm long in fruit; receptacle paleaceous, paleae lanceolate, margins hyaline, outer 3.5–4.0 mm long at flowering, 6–8 mm long in fruit. Ray florets 1–3 per capitulum, pistillate; ray limbs yellow, elliptic, 5–6 by 2.5–3.5 mm, basal tube 1 mm long. Disc florets ca 15 per capitulum; corollas yellow, ca 4.5 mm long, basal tube 1.2–1.5 mm long, apex 5-lobed. Achenes 11–18 by ca 1 mm, 3- or 4-angled, somewhat compressed, more-or-less short setuliferous; pappus of 3 or 4 awns, 3–4 mm long.

Thailand : EASTERN: Nakhon Ratchasima (Ban Khlong Duea); SOUTH-WESTERN: Kanchanaburi (Khao Kamphaeng, Bo Phloi).

Distribution : Widespread in the tropics and subtropics (USA – type), often a weed of cultivated land.

Ecology : Rocky slopes in bamboo thickets and on the ridges of limestone hills in dry evergreen forests, 800–1,500 m alt. Flowering: August–October.

Vernacular : Dao kra chai (ดาวกระจาย)(Central); pang-kuk-kho-nuai (ปังกุกโคหน่วย)(Chinese); ya laem nok sai (หญ้าแหลมนกไส้)(Northern).