Volume 8 > Part 1 > Year 2005 > Page 221 > Euphorbiaceae > Croton

27. Croton thorelii Gagnep.wfo-0000932549

Bull. Soc. Bot. France 68: 560. 1922; in Lecomte, Fl. Indo-Chine 5: 264, fig. 28. 8–10. 1925; Airy Shaw, Kew Bull. 26: 250. 1972, p.p. excl. Croton decalvatus; P.H.Hô, Câyco Vietnam 2, 1: 293, fig. 4460, 1992.

Accepted Name : This is currently accepted.

Description : Tree, up to 8 m high, bark brown, shallowly fissured; young branchlets densely pubescent, glabrescent. Indumentum consisting of stellate to stellate-lepidote, yellowish creamish hairs with paler radii, flat, 0.2–0.3 mm in diam., with ca 18–25 hardly to partially fused radii. Stipules 1 mm long, pubescent. Leaves irregularly crowded to pseudo-verticillate, a few leaves alternate; petiole 0.3–0.9 cm long, densely pubescent, slowly glabrescent; blade elliptic to slightly obovate, 10–20 by 2.5–4.5 cm, index 2.8–6.0, chartaceous, base acute with very base rounded-subcordate, margin distinctly serrate to subentire (teeth 5–15 mm apart), apex acute to subacuminate, of same colour on both surfaces, glabrous above, very sparsely pubescent below and soon glabrescent; basal glands sessile, flat to slightly elevated, ca 0.75 mm large, lateral on the abaxial midrib base, marginal glands absent; side veins 10–24 pairs, not triplinerved, tertiaries visible. Inflorescences whitish-green, 2–12 cm long, with 1–2 pistillate flowers, sometimes completely staminate, without bisexual bracts; densely pubescent throughout with only the bracts sometimes glabrescent; bracts 1.5–2 by 1 mm, stiff, eglandular or biglandular inside, persistent. Staminate flowers densely pubescent; pedicel 1–1.5 mm long; sepals ca 3 by 1–1.25 mm; petals 2.5 by 1 mm, pubescent throughout; stamens ca 12. Pistillate flowers densely pubescent; pedicel 1–1.5 mm long (2.5–3 mm in fruit); sepals ca 2.5 by 1 mm, nearly as long as the ovary; petals absent; ovary 2–3 mm long, densely pubescent; styles free; stigmas 1.5–2 mm long, bifid from nearly their base, their apex often flattened and bifid again (quadrifid). Fruits not seen, the remaining columella 5–5.5 mm long. Seeds not seen.

Thailand : NORTH-EASTERN: Sakon Nakhon (Phu Phan), Nakhon Phanom; EASTERN: Chaiyaphum (Nafoi); SOUTH-EASTERN: Prachin Buri (Kabin Buri), Sa Kaeo (Aranyaprathet, Krabin); PENINSULAR: Ranong (Ngao Falls).

Distribution : Cambodia (type), Vietnam.

Ecology : In dry evergreen forests, on rocky sites along streams, 50–500 m alt. Flowering: September–April.

Vernacular : Plao noi (เปล้าน้อย), plao tawan (เปล้าตะวัน), plao thapo (เปล้าท่าโพ), ta-kri-num (Southeastern).