Flora of Thailand
Euphorbiaceae
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K. Phattarahirankanok & K. Chayamarit
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Shrub, dioecious or monoecious. Indumentum simple hairs. Stipules very small. Leaves alternate, simple, petiolate; blade deeply lobed or not, basally with 2 glands, margin serrate to crenate, with glands in teeth beneath, basally 3- or 5-nerved. Inflorescences axillary to terminal, racemes or panicles, pedunculate to almost sessile, uni- or sometimes bisexual, staminate ones many-flowered, pistillate ones few-flowered. Flowers symmetric; sepals 5(6), connate at base, imbricate; petals absent. Staminate flowers small, pedicellate; sepals membranous, margin entire; disc annular and lobed or consisting of 5(6) free glands; stamens 921, filaments free, anthers oblong; pistillode absent. Pistillate flowers larger than staminate ones, shortly pedicellate; sepals chartaceous, margin entire to often lobed with glands, persistent and accrescent; ovary 3 locular; ovules 1 per locule; stigmas widening into shortly split wings. Fruits lobed capsules, septicidally and (partly to) completely loculicidally dehiscent, subglobose; columella persistent. Seeds subglobose, marbled, carunculate.
Five species in tropical Asia from Himalayas, Yunnan, Myanmar, Indochina to Malesia. Two species in Thailand. Classification: subfamily Crotonoideae, tribe Codiaeae.
N o t e. Formerly, at least four species were recognised for Thailand (Airy Shaw, 1972). However, the presence of more specimens showed that the overlap in characters (size, shape and texture of leaves, size of staminate flowers, accrescence of pistillate sepals) is to such a degree that former B. effusum, B. micranthum, and B. siamense had to be united. Moreover, older names became available, therefore all specific names have changed.
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1a. |
Staminate flowers with free disc glands. Fruits erect. Dioecious. Leaves never lobed |
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1b. |
Staminate flowers with annular, lobed disc. Fruits pendulous. Monoecious (to sometimes unisexual). Leaves often lobed |
1. Baliospermum calycinum Mόll.Arg., Flora 47: 470. 1864; in DC., Prodr. 15, 2: 1126. 1866; Kurz, For. Fl. Brit. Burma 2: 410. 1877; Hook.f., Fl. Brit. India 5: 462. 1887; Pax & K.Hoffm. in Engl., Pflanzer. IV.147.iv: 28. 1912; Brandis, Ind. Trees: 583. 1978; T.Chakrab. & N.P.Balakr., Bull. Bot. Surv. India 32: 13. 1990; Phattar. & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 121, plate V: 1. 2005. Baliospermum micranthum Mόll.Arg., Linnaea 34: 215. 1865; Airy Shaw, Kew Bull. 26: 222. 1972. Baliospermum corymbiferum Hook.f., Fl. Brit. Ind. 5: 463. 1887. Baliospermum siamense Craib, Kew Bull.: 467. 1911; Airy Shaw, Kew Bull. 26: 223. 1972. Baliospermum effusum Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.iv: 27. 1912; Airy Shaw, Kew Bull. 26: 222. 1972.
Shrub up to 3 m high, dioecious. Leaves: petiole 26(9) cm long; blade usually oblong to elliptic, slightly ovate or obovate, 1020 by 38 cm, chartaceous, base usually cuneate, rarely rounded, margin serrate to slightly crenate, apex acute to acuminate or slightly caudate, strigose on lower surface or both sides, trinerved or penninerved with 610 pairs of nerves, midrib prominent on both sides. Inflorescences glabrous to pubescent; staminate ones 116 cm long; pistillate ones 23 cm long. Staminate flowers globose, small, 0.82(3) mm in diameter; pedicels (0.5)12(3) mm long; sepals orbicular to ovate, 12.5 by 0.82 mm, subglabrous; disc free glands in a circle of 0.61.2 mm in diameter; stamens 921, filaments (0.2)12 mm long; anthers oblong, (0.3)0.6 ny c. 0.2 mm. Pistillate flowers larger than staminate ones, 37 mm in diameter; pedicels 12 mm long; sepals elliptic or oblong (or slightly ovate) , 35(8) by 12(4) mm, chartaceous, pubescent or almost glabrous, pale green to green-yellow; ovary subglobose, 13 mm in diameter, glabrous or slightly pubescent; style slender, 13 mm long. Fruits erect, subglobose, 1(1.2) by c. 0.8 cm; calyx persistent and accrescent up to 5(8) by 2(4) cm. Seeds subglobose, brown to dark brown, c. 4 by 3 mm.
T h a i l a n d. NORTHERN: Mae Hong Son (Pai), Chiang Mai (Doi Chiang Dao, Doi Inthanon, Doi Suthep), Lampang (Doi Luang, Chae Son), Tak (Doi Musoe), Kamphaeng Phet (Mae Wong), Phitsanulok (Phu Miang).
D i s t r i b u t i o n. India (type), Bangladesh, Nepal, China (Yunnan), Myanmar.
E c o l o g y. In dry evergreen to montane evergreen forest; in partly open areas, along streams or on hillsides. Altitude: 6502500 m. Flowering June- February; fruiting September- February.
V e r n a c u l a r. Plao tong taek (เปล้าตองแตก) (Chiang Mai).
N o t e s. Chakrabarty & Balakrishnan (1990) described two species in two sections and 9 varities from the Indian subcontinent. The formerly recognized species in Thailand, B. corymbiferum, B. effusum, B. micranthum, and B. siamense were reduced to varieties within a single species (B. calycinum). Characters used were mainly the width and length of male inflorescences and the shape of the leaf blades. The material investigated for this account showed these characters largely to overlap, therefore, only B. calycinum is recognized without any varieties.
2. Baliospermum solanifolium (Burm.) Suresh, Regnum Veg. 119: 106. 1988; Phattar. & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 121, fig. 25. 2005. Croton solanifolius Burm., Fl. Malab. 6. 1769. Jatropha montana Willd., Sp. Pl. 4: 563. 1805. Croton solanifolius (Burm.) Geiseler, Croton Monogr.: 74. 1807 (non J. Burm. 1769). Baliospermum axillare Blume, Bijdr.: 604. 1825. Croton polyandrus Roxb., Fl. Ind. ed. 2. 3: 682. 1832. Baliospermum indicum Decne. in Jacquem., Voy. Inde: 154, t. 155. 1841. Baliospermum moritzianum Baill., Ιtude Euphorb.: 395. 1858. Baliospermum montanum (Willd.) Mόll.Arg. in DC. Prodr. 15, 2: 1125. 1866; Airy Shaw, Kew Bull. 26: 222. 1972; Kew Bull. 37(1): 8. 1982; T.Chakrab. & Balakr., Bull. Bot. Surv. India 32: 5. 1990; P.H.Hτ, Cβyco Viκtnam 2: 351. 1992. Baliospermum polyandrum (Roxb.) Wight, Icon. Pl. Ind. Or. 5. 2: 23, t. 1885.
Monoecious (rarely dioecious) shrub up to 2 m high. Leaves: petiole 213 cm long; blade usually ovate to oblong, 821 by 310 cm, chartaceous, base usually rounded, rarely cuneate, margin serrate or crenate, frequently deeply 35-lobed, apex obtuse or acute, glabrous or strigose on both surfaces, venation basally 35-nerved, nerves 68 pairs along the midrib. Inflorescences glabrous to pubescent; staminate ones 18(16) cm long; pistillate ones 0.11 cm long. Staminate flowers 23 mm in diameter; pedicel 212 mm long; sepals orbicular to ovate, c. 1.5 by 1 mm; disc annular, cup-shaped, 11.5 mm in diameter; stamens 1012, filaments 0.51 mm long, anther oblong, c. 0.5 by 0.2 mm. Pistillate flowers 24 mm in diameter; pedicels 0.21 cm long; sepals 5, ovate or triangular, 12 by 0.81 mm, pubescent outside; ovary subglobose, 13 mm in diameter, pubescent; style stout, 1.53 mm long. Fruits pendulous, subglobose, 0.81.3 in diameter, calyx persistent, accrescent to (3)5 by 2(3) cm. Seeds ovoid, c. 3.5 by 3 mm, brown.
T h a i l a n d. Throughout the country.
D i s t r i b u t i o n. Pakistan, India (type), Bangladesh, Bhutan, Nepal, Sri Lanka, Myanmar, Cambodia, Laos, Vietnam, Malay Peninsular, Borneo, Sumatra, Java, Celebes, Moluccas, Lesser Sunda Islands.
E c o l o g y. In rather dry mixed deciduous to evergreen forests, occasionally with bamboo, or along forest margin, common in open areas. Altitude: sea level up to 900 m elevation. Flowering & fruiting: December-March.
V e r n a c u l a r. Tong taek (ตองแตก) (General); pho-bo-cho (พอบอเจ๊าะ), tho-khlo (โทะโคละ) (Karen-Mae Hong Son); long pom (ลองป้อม) (Loei); thon di (ถ่อนดี) (Central); nong pom (น่องป้อม), thon di (ทนดี) (Trang).
U s e s. The seeds are a drastic purgative, and used as a substitue for Croton tiglium L. Oil from the seeds and leaves is irritant when touching the skin.