Volume 8 > Part 1 > Year 2005 > Page 222 > Euphorbiaceae > Croton

28. Croton tiglium L.wfo-0000932555

Sp. Pl.: 1004. 1753; Müll.Arg. in DC., Prodr. 15(2): 600. 1866; Kurz, Forest Fl. Burma 2: 374. 1877; Ridl., Fl. Malay Penins. 3: 262. 1924; Gagnep. in Lecomte, Fl. Indo-Chine 5: 285. 1925; Burkill, Dict. Econ. Prod. Malay Pen. 1: 690. 1935; Airy Shaw, Kew Bull. 26: 250. 1972; Whitmore, Tree Fl. Malaya 2: 84. 1973; Corner, Wayside Trees Mal., ed. 3: 284. 1988; Chakrab. & N.P.Balakr., J. Econ. Taxon. Bot. 12: 367. 1988; P.H.Hô, Câyco Viêtnam 2, 1: 298, fig. 4476. 1992; Y.T.Chang, Fl. Reipubl. Popularis Sin. 44(2): 133. 1996; Chakrab. & N.P.Balakr., Bull. Bot. Surv. India 34: 72. 1997 (‘1992’); Welzen & Esser in Valkenburg & Bunyapraphatsara (eds.), Prosea 12(2): 202, fig. 2001.

Accepted Name : This is currently accepted.

Synonyms & Citations :

Description : Shrub or treelet, up to 6 m high, branched from base, bark greyish-green to tan, slightly roughened; branching crowded but usually not truely verticillate; young branchlets with scattered hairs, soon glabrescent. Indumentum consisting of stellate, yellowish-pale-brown hairs, often with a short central, porrect radius, 0.3–0.8 mm in diam., with 7–13 free radii. Stipules 0.5–1 mm long, subglabrous, caducous. Leaves alternate; petiole (1.2–)2.5–4.0 cm long, with scattered hairs or subglabrous; blade ovate-elliptic, 6–12 by 4–9 cm, index 1.2–2.0, membranous, base obtuse to subcordate with very base attenuate, margin shallowly serrate to subentire (teeth 2–5 mm apart), apex subacute to acuminate, slightly brighter below, with scattered hairs to subglabrous on both surfaces, sometimes densely pubescent on larger veins below; basal glands 0.75–1 mm in diam. and sessile to distinctly (by up to 3 mm) stalked, always lateral on the basal leaf margin close to but not on the midrib, marginal teeth often topped by small glandular tissue but without distinct additional glands; side veins (3–)4–6 pairs, very distinctly triplinerved. Inflorescences yellowish-green to whitish, erect, 7–15 cm long, with 2–15 pistillate flowers, often with bisexual bracts; the axis with scattered but distinct hairs or subglabrous; bracts 2–3(–4) by 0.5–1 mm, quite glabrous, eglandular, caducous to persistent. Staminate flowers subglabrous outside; pedicel 3 mm long; sepals 2.5–4 by 1.5 mm; petals 2 by 1 mm; stamens ca 12–15, glabrous. Pistillate flowers: pedicel 2–4 mm long (6 mm in fruit), distinctly pubescent; sepals 2.5–5 by 1–2 mm, slightly fused at base, subglabrous to slightly pubescent, slightly to distinctly longer than the ovary, membranous and usually spreading; petals absent; ovary 2.5 mm long, densely pubescent; stigmas 4–5 mm long, free, undivided for ca 1 mm at base or not at all, once bifid in the larger upper. Fruits 13–20 mm long, sulcate, surface subglabrous and smooth, pericarp very thin and fragile (less than 0.5 mm thick). Seeds 8–12 by 6–8 mm, ecarunculate.

Thailand : Widely cultivated; collected in probably natural environments in: NORTHERN: Phrae (Silo); EASTERN: Chaiyaphum (Ban Nam Phrom).

Distribution : Sri Lanka (type), India, through SE Asia to China, and Malesia from the Malay Peninsula to the Philippines and the Maluku.

Ecology : In evergreen forests, on sandstone, 600 m alt. Flowering and fruiting: May–August.

Vernacular : Hat sakhuen (หัสคืน), salot (สลอด); ba kang (บะกั้ง), ma kang (มะข่าง, มะคัง), mak thang (หมากทาง), matot (มะตอด)(Northern); mak pong, mak yong (หมากยอง)(Shan-Mae Hong Son); luk phlan sattru (ลูกผลาญศัตรู), mak lot (หมากลอด), salot ton (สลอดต้น)(Central).

CommonName : Croton oil plant.

Uses: Widely cultivated as ornamental tree and for medicinal purposes. The dried leaves are crushed and used medicinally as purgative, and are mentioned as poultice for snake bites. Because of the toxicity many former uses of, e.g., wood and root in human and veterinary medicine have been abandoned. The seeds are very poisonous (2–3 seeds are lethal) and used for stupefying fish in some parts of Malesia, but also used as a drastic hydragogue purgative for man. The seed oil (Croton oil) is irritant and causes dermatitis, but diluted it can be externally applied as counterirritant for various skin affections, and rubbed on the skin it acts as a rubefacient. It has been used for outdoor illumination (the fumes are irritant). A seed extract can de used as insecticide. Cultivation is possible on very poor soil and has been tried in former times in, e.g., Sri Lanka.

Notes: The plants formerly separated as Croton birmanicus (= C. himalaicus) differ slightly in a more distinct pubescence and usually stalked glands at the leaf base. The differences are not clearcut, and probably these taxa should be united. This had already been suspected by Airy Shaw (l.c.). It should be noted that in Malesia all plants confirm with the typical C. tiglium.