Volume 8 > Part 1 > Year 2005 > Page 218 > Euphorbiaceae > Croton

24. Croton roxburghii N.P.Balakr.wfo-0000932221

Bull. Bot. Surv. India 3: 39. 1962; Airy Shaw, Kew Bull. 32: 74. 1977; P.H.Hô, Câyco Viêtnam 2, 1: 298, fig. 4475. 1992 (as ‘roxburghianus’); Chakrab. & N.P.Balakr., Bull. Bot. Surv. India 34: 67. 1997 (‘1992’).

Accepted Name : Croton persimilis Müll.Arg.
Linnaea 34: 116. 1865.

Synonyms & Citations :

Description : Shrub or tree, up to 10(15) m high, dbh 25 cm, deciduous; bark thin, smooth, cracked with age, greyish to tan, inner bark pink; branching mostly verticillate; young branchlets densely pubescent, glabrescent. Indumentum consisting of lepidote hairs (rarely stellate lepidote on floral parts), pale-grey-brownish hairs, flat, 0.2–0.3 mm (on flowers 0.5 mm) in diam., with 30 or more largely to completely fused radii. Stipules 2 mm long, sparsely pubescent. Leaves alternate (sometimes only in an apical whorl); petiole 1.0–5.2 cm long, initially densely pubescent but soon glabrescent; blade elliptic, 10–32 by 4–12 cm, index 2.1–3.1, chartaceous, base acute to obtuse, margin distinctly serrate, the teeth 3–5(–7) mm apart, apex acute to rounded, only slightler brighter below, glabrous above, very sparsely pubescent to glabrous below; basal glands sessile, flat to slightly elevated, ca 1 mm large, lateral on the abaxial midrib base, marginal glands absent; side veins 15–18 pairs, not triplinerved, tertiaries visible. Inflorescences greenish-whitish, often several in an apical leafless whorl, erect, 9–36 cm long, with 9–23 pistillate flowers, sometimes completely staminate, without bisexual bracts; initially densely pubescent but axis soon glabrescent (not however the flowers); bracts 1–3 mm long, densely pubescent to glabrous, stiff, usually with a pair of disc-shaped, up to 1 mm large glands at base, slowly caducous. Staminate flowers: pedicel 2.5–5 mm long, densely pubescent; sepals 2.5–3 by 1.5 mm, ± glabrescent; petals 3 by 1 mm; stamens 10–12, glabrous or variously pubescent (rarely even on the anthers). Pistillate flowers: pedicel 2–4 mm long (3–5 mm in fruit), densely pubescent; sepals 2.5–3 by 1.5–2 mm, densely pubescent on their whole length, as long as or slightly longer than the ovary; petals often absent, when present 2 by 0.5 mm; ovary 2–2.5 mm long, densely pubescent; stigmas 3–4 mm long, not fused at base, undivided for 0.25–1.5 mm (up to half of length), once divided in the apical part. Fruits 6–7 by 6–7 mm, sulcate, surface sparsely but distinctly pubescent but otherweise smooth; pericarp quite thick. Seeds ca 6 by 4 mm, with a small caruncle.

Thailand : NORTHERN: Mae Hong Son, Chiang Mai, Chiang Rai, Phayao, Nan, Lamphun, Lampang, Phrae, Tak, Sukhothai, Phitsanulok, Kamphaeng Phet, Nakhon Sawan; NORTH-EASTERN: Phetchabun, Loei, Nong Khai, Sakon Nakhon, Nakhon Phanom, Mukdahan; EASTERN: Chaiyaphum, Nakhon Ratchasima; SOUTH-WESTERN: Uthai Thani, Kanchanaburi, Phetchaburi, Prachuap Khiri Khan; CENTRAL: Saraburi, Nakhon Nayok; SOUTH-EASTERN: Sa Kaeo, Chanthaburi.

Distribution : India (type from Calcutta), Nepal, Bhutan, Bangladesh, Burma, Laos, Cambodia, Vietnam.

Ecology : In mixed and dry deciduous forests, mixed evergreen/deciduous forests, dipterocarp-oak forests, disturbed hill and dry evergreen forests, Imperata or bamboo vegetation, fire-prone areas, secondary growths, road sides and old clearings, rocky slopes, dry or at streams; over limestone, sandstone, basalt or granite; 10–950 m alt. Flowering: November March. (May); fruiting: January–April. The flowers are scented or with foetid odor.

Vernacular : Plao (เปล้า), plao yai (เปล้าใหญ่); chi-mae-chi-cha, chi-mia-chi-yat-apa (Akha-Chiang Rai); say-ga-wa (Karen-Lamphun); plao luang (เปล้าหลวง)(Northern); khwa-wu (ควะวู)(Karen-Kanchanaburi); plao hua kwan (เปล้าหัวขวาน)(Prachuap Khiri Khan).

Uses: Leaves and heartwood used medicinally, e.g., externally for sprains. Pounded leaves are used for insect bites by the Akha; the boiled leaves give a bath for women after giving birth (by Karen, mixed with Zingiber, Antidesma, etc.), breathing of the boiling leaves helps recovering from fever, and mashed leaves together with salt, Cymbopogon etc. are used as plaster for broken bones by the Lahu. The seed oil is purgative.