Flora of Thailand Euphorbiaceae

 

5. Aleurites

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Genus description

Species description

Aleurites

J.R.Forst. & G.Forst., Char. Gen. Pl.: 56. 1776; Müll.Arg. in DC., Prod. 15, 2: 722. 1866; Hook.f., Fl. Br. India 5: 384. 1887; Pax in Engl., Pflanzenr. IV.147: 128. 1910; Airy Shaw, Kew Bull. 20: 393. 1967; Kew Bull. 26: 213. 1972; G.L.Webster, Ann. Missouri Bot. Gard. 81: 114. 1994; P.I.Forst., Muelleria 9: 6. 1996; Stuppy et al., Blumea 44: 79. 1999; Radcl.-Sm., Gen. Euphorbiacearum: 330. 2001; Stuppy et al. in Chayam. & Welzen, Fl. Thailand 8, 1: 49. 2005; G.L.Webster in Kubitzki, Fam. Gen. Vasc. Pl. 11: 182. 2014.— Camirium Rumph. ex Gaertn., Fruct. 2: 104. 1791.— Aleurites J.R.Forst. & G.Forst. sect. Camirium (Rumph. ex Gaertn.) Müll.Arg. in DC., Prod. 15, 2: 723. 1966, nom. inval.

Trees, monoecious. Indumentum consisting of stellate hairs. Stipules early caducous, minute, cylindrical. Petiole with 2 (3) sessile, discoid glands at apex. Leaves alternate, simple, symmetric, ovate, not lobed (or lobed), base cuneate to truncate (to emarginate), margin entire, apex acuminate, both sides smooth, hairy when young; nerves basally 3- or 5-palmate, pinnate along midrib with 4-8 nerves per side, looped and joined near the margin, veins scalariform. Inflorescences terminal, solitary, many-flowered branching, pyramidal thyrses, bisexual (or unisexual) with the flowers in bracteate clusters, protogynous with a solitary pistillate flower terminating each major axis, lateral cymules staminate. Flowers actinomorphic, white to cream; calyx valvate, rupturing into 2 or 3 (4) usually unequal lobes; petals 5 (6), obovate; disc 5-lobed, lobes free, inconspicuous. Staminate flowers pedicellate; disc lobes thick; stamens 17-32 in 4 whorls, outer ones free, inner ones united into a column, anthers 2-locular, basi- to dorsibasifixed, intrors; pistillode absent. Pistillate flowers usually somewhat larger than staminate ones, pedicellate; ovary 2- or 3(4)-locular, ovules 1 per locule, style present, stigmas split in upper part. Fruits large drupes, stellately hairy, exocarp thin, endocarp woody. Seeds subglobose to ovoid, dorsiventrally compressed or not, ecarunculate.

    Two species, one widespread through S.E. Asia (incl. Thailand), Malesia, and the Pacific, cultivated pantropically; the other restricted to Papua New Guinea and N.E. Australia (Queensland). Classification: Subfam. Crotonoideae, tribe Aleuritideae, subtribe Aleuritinae.

1. Aleurites moluccana (L.) Willd., Sp. Pl. 4: 590. 1804; Pax in Engl., Pflanzenr. IV.147: 129, fig. 45. 1910; Airy Shaw, Kew Bull. 20: 393. 1967; Kew Bull. 26: 213. 1972; Whitmore, Tree Fl. Malaya 2: 54. 1973; P.I.Forst., Muelleria 9: 7. 1996; Stuppy et al., Blumea 44: 80, fig. 1 j-m. 1999; in Chayam. & Welzen, Fl. Thailand 8, 1: 49, fig. 11. 2005.— Jatropha moluccana L., Sp. Pl.: 1006. 1753.— Aleurites triloba J.R.Forst. & G.Forst., Char. Gen. Pl.: 56, t. 56. 1776.— Juglans camirium Lour., Fl. Cochinch. 1: 573. 1790.

Cultivated, large tree up to 25(-40) m tall. Stipules c. 1 mm long. Leaves: petiole 3.5-16(-40) cm long, glands 0.5-2 mm in diameter; blade (6-)12-30 by 3-15(-28) cm, length/width ratio 1-4. Inflorescences 4-27 by 4-32 mm, densely hairy. Staminate flowers 5-10 mm in diameter; pedicel 4-12 mm long; calyx lobes 2.5-3 by 1.5-3 mm; petals (3.5-)-5-7(-9.5) by 1.2-3 mm; stamens 17-26, outermost filaments 0.5-1 mm long, inner most 2-3.5 mm long, anthers 0.6-0.8 by 0.3-0.6 mm. Pistillate flowers 7-10 mm in diameter; pedicels stout, 2-3.5(-6) mm long; calyx lobes 3-6 by 2-5 mm; petals 6-11 by 1.6-3 mm; ovary subglobose, laterally compressed, 2(3)-locular, 1.5-3 by 2-3.5 mm broad, stigmas deeply bifid, (0.5-)1-2.6 mm long. Fruits laterally compressed, broadly ovoid-subglobose or transversely ovoid with 4 (6) low longitudinal ridges, very slightly acuminate at the apex, 4-4.5 by 4-6(-7) cm. Seeds broadly obovoid, cordate in dorsal view, dorsiventrally compressed, truncate or rarely minutely tipped at the micropylar end, always tapering towards the obtusely acuminate chalazal end, (20-)23-32 by 20-32 by (15-)18-24 mm, greyish, mottled brownish.

    T h a i l a n d.— NORTHERN: Chiang Mai (Doi Chiang Dao, Mae Haut, Sameong, Tham Chieng Dao), Phrae; CENTRAL: Bangkok; PENINSULAR: (Tung Nai). Unknown whether cultivated or wild.

    D i s t r i b u t i o n.---Probably native of tropical Asia and Oceania, presently widely cultivated pantropically and subtropically.

    E c o l o g y.— Wild and cultivated o a variety of substrates and in many different kinds of vegetation, including plantations. Young plants are pioneers in the Australian vineforest. Altitude: 0-1000 m.

    V e r n a c u l a r.— Mayao (มะเัยา) (Northern); phothisat (โพธิสัตร์) (Central); pu rat (ปูรัด) (Satun); kue-ra (กือระำ) (Malay-Yala); Candlenut tree, Indian walnut, Varnish tree (English).

    U s e s.— Wood is used for tea boxes and canoes. The seeds are eaten raw or after roasting together with rice or used as purgative. The seeds are used as torches by wrapping them in leaves or stringing them to the midribs of palm leaves. The seeds contain a high amount of oil (60 %), which is used as fuel, lubricant, component of varnish, paint, and soap. The oil is also used as rubbing oil with rheumatism. The latex is chewed as gum in the Pacific, and is also used medicinally or as glue. Juice from the husk is used as a black dye, similarly from the bark of the root; the latter is used to paint canoes. Chinese in Hawaii let the wood of felled trees rot to grow the fungus Auricularia cornea (Ehrenb. ex Fr.) Ehrenb. ex Endl., for local consumption or for export to China. The tree is also used as an ornamental.