Flora of Thailand Euphorbiaceae

 

14. Blumeodendron

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Genus description

Identification key

Species descriptions

Blumeodendron

(Müll.Arg.) Kurz, J. Asiatic. Soc. Bengal 42: 245. 1873; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vii: 47. 1914; Airy Shaw, Kew Bull. 16: 348. 1963; Whitmore, Tree Fl. Malaya 2: 68. 1973; Airy Shaw, Kew Bull. Add. Ser. 4: 57. 1975; Kew Bull. Add. Ser. 8: 37. 1980; Kew Bull. 36: 267. 1981; G.L.Webster, Ann. Missouri Bot. Gard. 81: 77. 1994; Racl.-Sm., Gen. Euphorb.: 170. 2001; Chayamarit in Chayamarit & Welzen, Fl. Thailand 8, 1: 130. 2005.

Trees, dioecious.  Indumentum mainly absent, otherwise simple hairs.  Stipules absent.  Leaves alternate to seemingly opposite, often in pseudo-whorls; petiole on both ends strongly pulvinate; blade coriaceous, margin entire, without glands and domatia underneath, penninerved or basally 3- or 5-nerved.  Inflorescences axillary or terminal racemes or panicles. Flowers small, pedicellate; sepals 3–5, valvate; petals absent; disc present. Staminate flowers: disc glands many, among stamens; stamens 15–35, free, connective broad with thecae along it, thecae 2-celled; pistillode absent. Pistillate flowers: disc annular; ovary 2- or 3-locular with 1 ovule per locule; style present, stigmas spreading and recurving. Fruits large, tardily dehiscent, thick woody capsules, usually more than 3 cm in diameter, glabrous.

    A genus of 6 species from the Andaman Islands and Burma through Indonesia to the Bismarck Archipelago.  Two species in Thailand. Classification: subfam. Acalyphoideae, tribe Picnocomeae, subtribe Blumeodendrinae.

Key to the species

1. Blumeodendron kurzii  (Hook.f.) J.J.Sm., Meded. Depart. Landbouw 10: 458. 1910; Pax & Hoffm. in Engl., Pflanzenr. IV.147.vii: 47. 1914; Airy Shaw, Kew Bull. 16: 348. 1963; Whitmore, Tree Fl. Malaya 2: 68. 1973; Airy Shaw, Kew Bull. Add. Ser. 4: 57. 1975; Kew Bull. Add. Ser. 8: 37. 1980; Kew Bull. 36: 267. 1981; Chayamarit in Chayamarit & Welzen, Fl. Thailand 8, 1: 130. 2005; Fl. Thailand 8, 2: 611, Fig. 2. 2007.— Mallotus kurzii Hook.f., Fl. Br. Ind. 5: 427. 1887.

Tree 7–30 m high, branches glabrous. Leaves opposite or 3–4-verticillate; petiole 2–5 cm long, terete; blade rhomboid, broadly elliptic or ovate, 8–19.5 by 3.5–12 cm, coriaceous, glabrous, base obtuse or cuneate, with 2 small blotch-like glands above, margin not pale, apex abruptly acuminate with obtuse tip to 1.5 cm long, usually drying grey-green, shiny above; nerves 3–5 pairs, reticulation obscure, midrib very distinct and rounded benath. Staminate inflorescences axillary and lateral on thickened nodes, fascicled, very short, paniculate, peduncle short, many flowers, glabrous. Staminate flowers: pedicels 4–7 mm long, glabrous; sepals 3, ovate, c. 4.5 mm long, reflexed, glabrous; stamens c. 30. Pistillate inflorescences fascicled or in short panicles, peduncle 5–9 mm long, few to many flowers. Pistillate flowers: calyx cup-shaped, 4-lobed or 4-dentate, c. 1 mm high, glabrous; disc 4-lobed; ovary oblong, flattened, mainly 2-locular; stigmas 2. Fruits rounded, flattened, c. 4.5 by 3.5 cm, 1.5 cm in diameter, hard, with remnant of style, stalk stout, 5 mm long. Seeds subreniform.

    T h a i l a n d.— PENINSULAR: Satun (Klong Ton, Kraburi, Klong Na), Phatthalung (Klong Hin Khao).

    D i s t r i b u t i o n.—

    E c o l o g y.— In evergreen forest; alt. 150–200 m. Flowering: March; Fruiting: April.

    V e r n a c u l a r.— Khun thaen (ขุนแท่น) (Narathiwat); ya-ka (ยากา) (Malay-Narathiwat).

2. Blumeodendron tokbrai (Blume) J.J.Sm., Meded. Depart. Landbouw 10: 458. 1910; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vii: 47. 1914; Airy Shaw, Kew Bull. 16: 348. 1963; Whitmore, Tree Fl. Malaya 2: 68. 1973; Airy Shaw, Kew Bull. Add. Ser. 4: 57. 1975; Kew Bull. Add. Ser. 8: 37. 1980; Kew Bull. 36: 267. 1981; Chayamarit in Chayamarit & Welzen, Fl. Thailand 8, 1: 131. 2005; Fl. Thailand 8, 2: 612, Fig. 3. 2007. — Elateriospermum tokbrai Blume, Bijdr.: 621. 1825.

Tree 10–18 m high, bole fluted, sometimes with small buttresses, often with stilt-rooted; crown dense, small; bark warm orange brown, smooth, sometimes eye-marked, very fine rugulose; inner bark granular, soft, grayish brown. Leaves spirally arranged, opposite or 3-verticillate; petioles 1.5–5.5 cm long, slender to stout, grooved above; blade oblong to elliptic, 7–17 by 3.5–11.5 cm, coriaceous, base cuneate, not glandular, margin opten pale whitish when fresh and dry, apex more or less abruptly acuminate with obtuse tip, shiny above, glabrous or sparsely pilose on nerves, usually drying brown to grey-green, young leaves purplish; nerves 6–8, arched to the margin, prominent beneath, reticulation distinct. Staminate inflorescences racemes, 2.5–20 cm long, solitary or 2 together; flowers in groups of 1–3. Staminate flowers: pedicels 2–14 mm long; sepals 4, oblong, lanceolate or ovate, 4–5 mm long, reflexed, glabrous; stamens 14–18. Pistillate inflorescences axillary to terminal, very short, 3–9 flowers; peduncle 1–2.5 cm long. Pistillate flowers: sepals 3–5, oblong or linear triangular, 1–4 mm long, recurved, margin and outside puberulous; disc annular, fleshy, some denticulate warts; ovary ovoid, acute, mainly 3-locular, glabrous; stigmas 3. Fruits round, green, very slightly flattened, 3.5–5 by 3–4.5 cm, grooved or strongly keeled sutures, ripening orange. Seeds bean-shaped, 25–27 by c. 17 mm, black, enclosed in cream jacket.

    T h a i l a n d.— Narathiwat (Kok Dan Peat Swamp Forest).

    E c o l o g y.— Common in Peat swamp forest. Flowering in September; Fruiting in February.

    V e r n a c u l a r.— Ya ka (ยากา).

    U s e s.— Fruit is stated to be edible.