Flora of Thailand

Euphorbiaceae

 

76. Sampantaea

 

P.C. van Welzen

 

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Genus description

Species description

 

Sampantaea

 

Airy Shaw, Kew Bull. 26: 328. 1972; Hook. Icon. Pl. 38: t. 3717. 1974; G.L.Webster, Ann. Missouri Bot. Gard. 81: 86. 1994; Radcl.-Sm., Gen. Euphorbiacearum: 212. 2001; Welzen in Welzen & Chayam., Fl. Thailand 8, 2: 520. 2007; G.L.Webster in Kubitzki, Fam. Gen. Vasc. Pl. 11: 118. 2014.

 

Shrubs to treelets, dioecious, candelabriform-branching strong. Indumentum of simple, sericeous hairs, glabrescent. Stipules triangular, hairy outside and along margin, early caducous. Leaves alternate, simple; petiole completely, slightly pulvinate; blade symmetric, leathery, base (narrowly emarginate to) cuneately decurrent, margin serrate to almost entire, with glandular teeth, apex narrowly emarginate to acute, mucronulate, lower surface subglabrous with basally 1-4 circular glands, pocket domatia with hairy margin in nerve axils, nerves pinnate, looped and joined near margin, veins scalariform, veinlets reticulate, distinct. Inflorescences racemes, 1 or 2 axillary; bracts and bracteoles ovate, mainly margin hairy. Flowers one flower per node, actinomorphic, pedicelled; sepals 4 or 5, valvate; petals and disc absent. Staminate flowers: stamens 18-20, filaments short; anthers 2-celled, extrorse, connective slightly elongated; pistillode absent. Pistillate flowers: ovary 3-locular, shortly subsericeous, 1 ovule per locule; style short; stigmas papillate, 2/3rd bifid. Fruits rhegmas, thin-walled, shortly sericeous. Seeds naked.

    A monotypic genus known from Thailand and Cambodia. Classification: Subfam.: Acalyphoideae, tribe Acalypheae, subtribe Cleidiinae.

 

Sampantaea amentiflora (Airy Shaw) Airy Shaw, Kew Bull. 26: 328. 1972; Hook. Icon. Pl. 38: t. 3717. 1974; Welzen in Welzen & Chayam., Fl. Thailand 8, 2: 521, Fig. 71. 2007. Alchornea (?) amentiflora Airy Shaw, Kew Bull. 20: 45. 1966; Kew Bull. 61: 400. 1968.

 

Sampamen-habit.gif (151198 bytes)    Sampamen-male.gif (82674 bytes)    Sampamen-female.gif (87823 bytes)

 

Shrubs to small trees, up to 5 m high; flowering branches c. 3 mm thick. Stipules 4-7 by 1.5-3 mm. Leaves: petiole 1-6 cm long, above flat; blade obovate, 3.7-19 by 1.4-7.5 cm, ratio (1.7-)2-3.3; nerves 11-14 per side. Staminate inflorescences up to 6 cm long (in bud), pendulous; bracts c. 2 by 1.7-1.9 mm; bracteoles 1.3-1.9 by 1.3-1.7 mm. Staminate flowers green to whitish; pedicel c. 3 mm long; sepals ovate, c. 3 by 1.2-1.4 mm; filaments c. 0.5 mm long, anthers c. 1.3 mm long, connective appendix c. 0.3 mm long. Pistillate inflorescences up to 3(-14 in fruit) cm long; bracts 1.2-1.6 by c. 1.5 mm, bracteoles 1-1.2 by c. 0.6 mm. Pistillate flowers greenish; pedicel 0.8(-6 in fruit) mm long; sepals ovate to elliptic, 2.1-2.3 by c. 1.2 mm; ovary c. 1.2 by 0.8 mm high; style 0.4-0.5 mm long; stigmas 4-5 mm long, upper 3 mm split. Fruits green, c. 10 by 6 mm; column c. 3.5 mm long, basally slender, apically broadly obtriangular. Seeds ellipsoid, c. 5 by 4.2 mm.

    T h a i l a n d. NORTH-EASTERN: Sakon Nakhon (Phu Phan National Park), Nakhon Phanom (Dong Bang Ee), Mukdahan (Khamchae); EASTERN: Nakhon Ratchasima (Lat Bua Kao, Pak Chong, Pak Thong Chai); CENTRAL: Phra Nakhon Si Ayutthaya (Chaibadan), Saraburi (Ban Nawng Bua); SOUTH-EASTERN: Sa Kaeo (Aranyaprathet, Tarueang), Prachin Buri (Ikao Bep), Chachoengsao (Khao Hin Son).

    D i s t r i b u t i o n. Thailand (type: Lat Bua Kao, Nakhon Ratchasima, PUT 4347, holo in K, iso in BK), Cambodia.

    E c o l o g y. (Mixed) evergreen forest. 150-400 m.

    V e r n a c u l a r. Sam pan ta (สามปันตา), sam phan ta (สามพันตา) (General); sam phan sa (สามพันสา) (Peninsular).