Volume 8 > Part 1 > Year 2005 > Page 86 > Euphorbiaceae > Aporosa

3. Aporosa duthieana King ex Pax & K.Hoffm.wfo-0000248603

in Engl., Pflanzenr. IV. 147. xv: 99. 1922.

Accepted Name : This is currently accepted.

Description : Trees, up to 20 m high, very sparsely puberulous. Stipules not seen, caducous. Leaves: petiole 7–25 mm long, reniform, glabrescent, pulvini distinct; blade ovate to elliptic, 7–19.5 by 2–6.5 cm, length/width ratio 2.6–3.5, coriaceous, drying blackish above, brownish beneath, base obtuse to cuneate, basal glands absent, margin lowly undulate to irregularly crenulate, marginal glands few, black, apex acuminate, upper surface glabrous, lower surface very sparsely puberulous on midrib and nerves at most, with very small disc glands along margin, more than 1 mm from margin; venation prominent on both sides, nerves 5–7 pairs. Inflorescences axillary. Staminate inflorescences 1–4 together, 25–50 by 3–4 mm, sparsely puberulous; peduncle 0–10 mm long; bracts triangular, ca 0.6 mm long; glomerules with up to 15 (or more?) densely set flowers, basally spaced up to 5(–11)mm to apically continuous along rachis. Staminate flowers 2.2–3.8 mm long, sessile, yellow; sepals 4(5), elliptic, 0.9–1.3 mm long; stamens 2–4, long exserted, 2.2–3.8 mm long; anthers ca 0.5 mm long; pistillode absent. Pistillate inflorescences up to 18 mm long, single, tomentose; flowers up to 9, rather densely arranged at apical end; bracts triangular, 0.5–0.8 mm long; pedicel small, tomentose. Pistillate flowers not seen; fruiting pedicels 1–4 mm long; sepals 3 or 4, ovate, patent, 0.8–1.2 mm long; ovary 2-locular, sparsely puberulous; stigmas 2–2.5 mm long, bifid to ca halfway. Fruits ellipsoid, not stiped, slightly beaked, 10–12 by 7–8 mm, drying brown to black, sparsely puberulous at base, glabrescent, not fleshy, septae and column glabrous. Seeds ca 8 by 5–5.5 by 4 mm.

Thailand : SOUTH-EASTERN: Chanthaburi (Khao Soi Dao, PongNam Ron).

Distribution : Burma (type), Indochina.

Ecology : Evergreen forests, 800–1,000 m alt.

Vernacular : Mueat dut (เหมือดดูด).

Notes: Resembles Aporosa microstachya very closely, but differs in the thicker leaves and the glands at the lower leaf surface which are set more than 1 mm from the margin (leaves thin, with glands touching the margin in A. microstachya). The staminate inflorescences are also very distinct, with long exserted stamens and basally well-spaced glomerules in A. duthieana. An overlapping, but distinctive character is the length of the fruiting pedicel (up to 4 mm in A. duthieana, up to 1(–1.5) mm in A. microstachya). Aporosa duthieana is a very rare species in Thailand, up to now only known from two specimens.