Flora of Thailand

Euphorbiaceae

 

80. Sumbaviopsis

 

P.C. van Welzen

 

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Genus description

Species description

 

Sumbaviopsis

 

J.J.Sm., Meded. Dept. Landb. Ned.-Indië 10: 356. 1910; Pax & K.Hoffm. in Engl., Pflanzenr. IV.147.vi: 13. 1912; Gagnep. in Lecomte, Fl. Indo-Chine 5: 418. 1926; Airy Shaw, Kew Bull. 26: 341. 1972; Whitmore, Tree Fl. Mal. 2: 132. 1973; G.L.Webster, Ann. Missouri Bot. Gard. 81: 73. 1994; Welzen, Blumea 44: 426. 1999; Radcl.-Sm., Gen. Euphorbiacearum.: 148. 2001; Welzen in Welzen & Chayam., Fl. Thailand 8, 2: 562. 2007; G.L.Webster in Kubitzki, Fam. Gen. Vasc. Pl. 11: 142. 2014.

 

(Shrubs to) trees, monoecious. Indumentum of stellate hairs and probably simple ones. Stipules early caducous, scars very indistinct. Leaves alternate, simple; petiole relatively long, basally and apically pulvinate; blade ovate (to elliptic), papery, symmetric, base peltate, margin (sub)entire to dentate, with few glands along the margin or on the apex of teeth, glabrescent above, very densely, whitish hairy below, with dark yellow round glands near the base and along the margins near the nerves; venation pinnate, nerves indistinctly looped and connected near margin, veins scalariform, quaternary veins reticulate. Inflorescences terminal or (pseudo)axillary, pendent, thyrsoid when staminate, raceme-like when pistillate, single or 2 together, not (or hardly) branching with either staminate or pistillate flowers; staminate flowers up to 3 per cymule, pistillate flowers single per cymule. Flowers actinomorphic; disc absent. Staminate flowers: sepals 3-5, valvate; petals 4 or 5, ovate, much shorter than sepals; stamens c. 75, free, on a torus; pistillode absent. Pistillate flowers: sepals 5(6), imbricate; petals absent; ovary 2- or 3-locular, one ovule per locule, smooth, tomentose. Fruits lobed rhegmas, outside densely floccose, inside glabrous except at the base few hairs. Seeds covered by a thin, fleshy sarcotesta.

    Monotypic genus found in S.E. Asia and W. Malesia. Classification: Subfam. Acalyphoideae, tribe Chrozophoreae, subtribe Doryxylinae.

 

Sumbaviopsis albicans (Blume) J.J.Sm., Meded. Dept. Landb. Ned.-Indië 10: 357. 1910; Pax & K.Hoffm. in Engl., Pflanzenr. IV. 147.vi: 14. 1912; Pflanzenr. IV.147.vii: 424. 1914; Gagnep. in Lecomte, Fl. Indo-Chine 5: 418, fig. 49: 13-18. 1926; Airy Shaw, Kew Bull. 26: 341. 1972; Whitmore, Tree Fl. Mal. 2: 132. 1973; Welzen, Blumea 44: 428, fig. 4, map 3; in Welzen & Chayam., Fl. Thailand 8, 2: 562, Fig. 87, Plate XXX: 1. 2007.Adisca ? albicans Blume, Bijdr.: 611. 1825.— Sumbavia macrophylla Müll.Arg., Flora 47: 482. 1864.— Coelodiscus speciosus Müll.Arg., Linnaea 34: 154. 1865.— Sumbaviopsis albicans (Blume) J.J.Sm. var. disperma Gagnep. in Lecomte, Fl. Indo-Chine 5: 420. 1926.— Doryxylon albicans (Blume) N.P.Balakr., Bull. Bot. Surv. India 9: 58, fig. 1-7. 1967.

 

Sumbalbi-habit.gif (64965 bytes)    Sumbalbi-flower.gif (89398 bytes)    Sumbalbi-fruit.gif (90078 bytes)   

 

(Shrubs to) trees up to 27 m high. Stipules c. 0.6 by 0.4 mm. Leaves: petiole 1.2-11.2 cm long; blade 6.8-37 by 3.2-19 cm, length/width ratio 1.6-2.6, peltate by 2-8 mm, apex acuminate to cuspidate, venation impressed above, raised below, nerves 10-12 per side. Staminate inflorescences up to 16 cm long, pistillate ones up to 38 cm long. Staminate flowers 8-11 mm in diameter; pedicel c. 2.2 mm long; sepals ovate, 4.2-5.8 by 2-3.2 mm, brown; petals 1.7-2.8 by 1.7-2.5 mm, pale green; stamens: filaments 2.5-2.8 mm long, white, anthers 1-1.1 by 0.4-0.6 mm, white to yellow; torus up to 1.4 mm high. Pistillate flowers c. 3.3 mm in diameter; pedicel 2.8-3.5(-4.2 in fruit) mm long; sepals ovate, 2.3-4 by 1.5-2.5 mm; ovary 2.7-4.5 by 2.7-3.5 mm wide; style 0.8-1.6 mm long, stigmas spreading, up to 3 mm long with up to the last 1 mm split. Fruits 2.1-3.6 by 1.4-3 cm, bright to dark brown, tomentum light brown. Seeds 12-20 by 12-15 mm, black.

    T h a i l a n d.— NORTHERN: Chiang Mai, Lampang, Phrae, Phitsanulok, Tak; NORTH-EASTERN: Phetchabun, Khon Kaen; EASTERN: Chaiyaphum, Nakhon Ratchasima, Ubon Ratchathani; SOUTH-WESTERN: Kanchanaburi, Phetchaburi; CENTRAL: Saraburi; SOUTH-EASTERN: Chon Buri, Chanthaburi, Trat; PENINSULAR: Chumphon, Ranong, Trang, Songkhla, Pattani.

    D i s t r i b u t i o n.— N.E. India, Myanmar, Thailand, Vietnam, Malay Peninsula, N. Sumatra, Java (type), Borneo (Kalimantan Timur, Sabah, Sarawak), and the Philippines (Palawan).

Sumbalbi-map.gif (86863 bytes)

    E c o l o g y.— Scattered to locally common in primary mixed Dipterocarp forest, gallery forest, dry and/or mixed evergreen forest, secondary forest; in and at the margins of forest (even with heavy undergrowth), open places, along ridges, and along streams; terrain level to hilly; soil (may be thin): limestone, shale, sandstone, yellow-red loam. Altitude: sea level up to 800 m.

    V e r n a c u l a r.— Kra dat (กระดาษ), tong pha (ตองผ้า) (Lampang); khrok takua (ครกตะกั่ว), (Phitsanulok); sakua (สะกัว), takua (ตะกัว) (Nakhon Ratchasima); pang tua phu (ปังตัวผู้) (South-eastern).

    U s e s.— The seeds are edible.