e-Flora of Thailand

Volume 8 > Part 1 > Year 2005 > Page 105 > Euphorbiaceae > Aporosa

20. Aporosa yunnanensis (Pax & K.Hoffm.) F.P.Metcalfwfo-0000249884

Lingnan Sci. J. 10: 486. 1931; Airy Shaw, Kew Bull. 26: 218. 1972.— Aporosa wallichii var. yunnanensis Pax & K.Hoffm. in Engl., Pflanzenr. IV. 147. xv: 90. 1922. Fig. 21. D-F


Accepted Name : This is currently accepted.


Description : Shrub to tree, up to 8 m high; young branches glabrous. Stipules narrowly triangular, 24 by ca 1 mm, caducous. Leaves: petiole terete, 5–16 mm long, pulvini distinct; blade ovate (to elliptic), 7.5–17 by 2–5.5 cm, length/width ratio 3.1–3.8, papery, drying light greenish brownish above and beneath, base acute to slightly attenuate, basal glands present, margin slightly undulate to crenulate, marginal glands regular, apex cuspidate, completely glabrous, disc-like glands occasionally within marginal arches; venation especially raised beneath, nerves in 7–10 pairs. Inflorescences axillary. Staminate inflorescences 1–3 together, 18–41 by 1.8–2.5 mm, sericeous; peduncle absent; bracts triangular, 1–1.2 mm long; glomerules with ca 5 laxly set flowers, continuously set along rachis. Staminate flowers 1.2–2 mm long, sessile, yellowish; sepals 4 (or 5), obovate, 0.8–1.2 mm long; stamens 2, exserted, 1–2.2 mm long; anthers 0.3–0.4 mm long; pistillode indistinct. Pistillate inflorescences single (or 2 together), 2–5 mm long, sericeous, flowers up to 5, densely set along rachis; bracts triangular, 0.8–1.2 mm long. Pistillate flowers 4–6.5 mm long, sessile; sepals 3 or 4, ovate, subequal, ascending, 0.6–1.1 mm long; staminodes occasionally 1; ovary 2-locular, glabrous; stigmas raised, 1.5–2.5 mm long, apically bifid to near base. Fruits ovoid to ellipsoid, not stiped, beaked. 10–13 by 7.9 mm, reddish, drying light to reddish brown. glabrous, not fleshy; septae and column sparsely hairy. Seeds 7.5–9 by 5–6 by 4–4.5 mm.


Thailand : NORTHERN: Chiang Rai (Doi Tung), Nan (Doi Tin); EASTERN: Nakhon Ratchasima (Bo Rai, Khao Laem, Khao Yai NP); SOUTH-WESTERN: Kanchanaburi (Sangkhla); SOUTH-EASTERN: Chanthaburi (Khao Soi Dao, Pong Nam Ron); PENINSULAR: Phangnga (Khao Katakuam, Khao Po Ta Luang Kaeo).


Distribution : South China (type), Burma, Indochina.


Ecology : In evergreen forests; in wet or dry, shaded or open, or high areas, on gentle slopes, along edge of forests, stream, or road; on sandy or dry clayey soil, granite bedrock; 600–1,300 m alt.


Vernacular : Mueat bai leam (เหมือดใบแหลม)(Northern); nam phueng khao (น้ำผึ้งขาว)(Trang).


Notes: The papery leaves of Aporosa yunnanensis with cuspidate apex and greenish-grey colour with lighter venation distinguishes it from the A. octandra-complex.


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