Flora of Thailand Euphorbiaceae

 

13. Blachia

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Genus description

Identification key

Species descriptions

Blachia

Baill., Étude Euphorb. 385. 1858, nom. cons.; Hook.f., Fl. Br. Ind. 5: 402. 1887; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.iii: 36. 1911; Gagnep. in Lecomte, Fl. Indo-Chine 5: 410. 1926; Airy Shaw, Kew Bull. 23: 121. 1969; Kew Bull. 26: 223. 1972; Whitmore, Tree Fl. Mal. 2: 68. 1973; Airy Shaw, Kew Bull. Add. Ser. 4: 57. 1975; G.L.Webster, Ann. Missouri Bot. Gard. 81: 107. 1994; Philcox in Dassan & Fosberg, Rev. handb. Fl. Ceylon 11: 105. 1997; Radcl.-Sm., Gen. Euphorbiacearum: 304. 2001; Phattar. & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 126. 2005; Thin, Taxon. Euphorb. Vietnam: 260. 2007; G.L.Webster in Kubitzki, Fam. Gen. Vasc. Pl. 11: 176. 2014; Welzen, Blumea 59 (2015) 163. — Bruxalnellia Dennst. ex Kostel., Allg. Med.-Pharm. Fl. 5: 2002. 1830, nom. rej.

Shrubs to shrubby trees, mainly monoecious; without latex.  Indumentum simple hairs or absent. Stipules absent (Thailand). Leaves spiral; petiole short, not or hardly pulvinate; blade with entire margin, lower surface glabrous. Inflorescences terminal, umbellate or cymose; usually bisexual with staminate flowers above and pistillate flowers below; bracts absent. Staminate flowers pedicellate; sepals 5(6), imbricate, membranous, margin entire; petals 5(6), free, shorter than sepals, membranous; disc glands 5(6); stamens 14–24 (Thailand), filaments free, anthers opening latrorsely with longitudinal slits; pistillode absent. Pistillate flowers pedicellate; sepals 4–6, triangular, persistent, often accrescent in fruit (not in Thailand); petals absent; disc annular, 5- or 6-lobed; ovary (2)3-locular (Thailand), ovules single per locule; stigmas free, bifid. Fruits capsules, lobed or rather globose, > 3 cm diameter; septicidally dehiscent into 2-valved cocci; columella persistent. Seeds brown; ecarunculate.

    Twelve species in tropical asia from India to China (Hainan), Philippines and Borneo. Two species in Thailand. Classification: Subfam. Crotonoideae, tribe Codiaeae.

Key to the species

1. Blachia andamanica (Kurz) Hook.f., Fl. Brit. Ind. 5: 403. 1887; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.iii: 36. 1911; Gagnep. in Lecomte, Fl. Indo-Chine 5: 416. 1926; Airy Shaw, Kew Bull. 23: 121. 1969; Kew Bull. 26: 223. 1972; Kew Bull. 37: 9. 1982; Phattar. & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 127, fig. 27, plate VII: 1. 2005; Welzen, Blumea 59 (2015) 164, fig 1h.— Codiaeum andamanicum Kurz, For. Fl. Brit. Burm. 2: 405. 1877.— Dimorphocalyx andamanicus (Kurz) Benth. in Benth. & Hook.f., Gen. Pl. 3: 302. 1880.

Shrubs or shrubby trees, up to 5 m; bark smooth, grey.  Leaves: petiole 0.5–1 cm long; glabrous; blade obovate-oblong to obovate; 10–22 by 3–9 cm, rather coriaceous, base cuneate or rounded, without glands or stipellae, margin glabrous, apex obtuse to acuminate, glabrous on both surfaces, nerves 6 or 7 pairs, midrib prominent on both sides.  Inflorescences cymose or umbellate, glabrous; staminate inflorescences c. 3.5 cm long, peduncle 2–2.3 cm long; pistillate inflorescences subsessile. Staminate flowers 2–5 mm in diameter, pedicel 5–6 mm long; sepals orbicular, pale green; petals orbicular, white to light yellow; disc glands oblong, c. 1 by 0.5; mm stamens 17–24, filament 3–3.5 mm long, slender, anthers c. 0.5 by 0.5 mm. Pistillate flowers 1.5–4 mm in diameter; pedicel 2–5 mm long; sepals 5, ovate, c. 1 by 0.5 mm, green, margin glabrous, caducous; disc glands c. 1 by 0.5 mm; ovary 2- or 3-locular, subglobose, glabrous (rarely pubescent); stigmas filiform, 2–3 mm long.  Fruits subglobose, 0.8–1.5 cm in diameter, green, glabrous.  Seeds ovoid, c. 6 by 4 mm long.

    T h a i l a n d.— NORTHERN: Chiang Mai (Doi Chiang Dao), Nan (Tham Phatup Forest Park); NORTH-EASTERN: Loei (Wang Sapung); SOUTH-WESTERN: Uthai Thani (Khao Pla Ra), Prachup Khiri Khan (Huai Yang Waterfalls); PENINSULAR: Phuket, Satun (Tarutao National Park).

    D i s t r i b u t i o n.— Assam, Andamans (type), Myanmar, Malay Peninsula, Borneo, Philippines, Celebes, Moluccas, Lesser Sunda Islands..

    E c o l o g y.— Common in open dry evergreen forest and bare granite boulders, or on limestone. Altitude: up to 300 m. Flowering September-February; fruiting February.

    V e r n a c u l a r.— Kra liang phan (กระเลียงฟาน) (Peninsular).

2. Blachia siamensis Gagnep., Bull. Soc. Bot. France 620. 1924; in Lecomte, Fl. Indo-Chine 5: 415. 1926; Airy Shaw, Kew Bull. 26: 223. 1972; Phattar. & Chayam. in Chayam. & Welzen, Fl. Thailand 8, 1: 127, fig. 28, plate VII: 2. 2005.— Blachia jatrophifolia Pax var. siamensis Craib, Bull. Misc. Inf. Kew: 98. 1924.

Shrubs to shrubby trees, up to 5m high; bark fissured, brown to grey.  Leaves: petiole 0.3–1 cm long, usually pubescent; blade rhomboid-obovate, (2–)4–4.5 by (1–)2–3 cm, chartaceous, pubescent or almost glabrous, base cuneate, with 2 small stipellae or glands, margin ciliate, apex obtuse or acute; nerves 5–9 pairs, midrib prominent on both sides.  Inflorescences umbellate, pubescent; staminate inflorescences c. 2 cm long, peduncles 0.1–0.5(–1) cm long; pistillate inflorescences 1.5–2 cm long, peduncles 0.1–0.7 mm long. Staminate flowers 4–5 mm in diameter, pedicel 1.2–1.4 cm long, sepals 5 or 6, orbicular, 1.5–1.7 by 1–1.2 mm, , revolute, membranous, pale green; petals orbicular, 1.5–1.7 by 1–1.2 mm, membranous, pale yellow-green; disc glands c. 0.8 x 0.4 mm; stamens 14–21, filaments c. 3 mm long, anthers c. 0.5 by 0.5 mm long. Pistillate flowers 1–3.5 mm in diameter; pedicel 5–13(–23) mm long; sepals 5 or 6, ovate to slightly triangular, 2.5–4 by 1–1.3 mm, margin ciliate; disc glands c. 0.8 by 0.4 mm; ovary subglobose, 1.5–1.7 ´ 0.3–1 mm, pubescent, stigmas filiform, 5–6 mm long, green.  Fruits subglobose, 0.8–1 cm in diameter, pubescent; calyx persistent.  Seeds oblong to subglobose, c. 6 by 4 mm.

    T h a i l a n d.— SOUTH-WESTERN: Phetchaburi, Prachuap Khiri Khan (Huai Yang Waterfalls); SOUTH-EASTERN: Chon Buri (Sattahip, Ko Pai).

    D i s t r i b u t i o n.— S. China (Hainan).

    E c o l o g y.— Common in open dry evergreen forest, between bare granite boulders, frequently along streams. Altitude: sea level up to 100 m. Flowering March; fruiting March-July.

    V e r n a c u l a r.— Kra chit (กระชิด), khi rat (ขี้แรด) (Prachuap Khiri Khan).