Volume 13 > Part 4 > Year 2017 > Page 573 > Dipterocarpaceae > Dipterocarpus

2. Dipterocarpus alatus Roxb. ex G.Donwfo-0000651281

Gen. Hist. 1: 813. 1831; Pierre, Fl. Forest. Cochinch. 3: t. 212. 1889; Craib, Fl. Siam. 1: 133. 1925; Smitinand, Santisuk & Phengklai, Thai Forest Bull., Bot. 12: 31. 1980; Smitinand, J.E.Vidal & P.H.Hô, Fl. Cambodge, Laos & Vietnam 25: 41. 1990; Smitinand, Tompsett & Cheek, Kew Bull. 48: 398. 1993; K.P.Janardhanan, Fl. India 3: 209. 1993; Svengs. & J.E.Vidal, Diptérocarp. Laos: 18. 1997; Pooma & M.F.Newman, Thai Forest Bull., Bot. 29: 120. 2001; Gardner, Sidisunthorn & Chayamarit, Forest Trees S. Thailand Vol. 1: 419, fig. 644. 2015. Plate XLIV: 1–3.

Accepted Name : This is currently accepted.

Synonyms & Citations :

Description : Tree to 40 m tall. Indumentum short tufted tomentose and pubescent, densely on young twigs, buds, stipules, lower surface of leaves, especially on midrib and secondary nerves, inflorescences and calyx tube. Buds 1–2 cm long. Stipules lanceolate, 5–11 by 1.5–2.5 cm. Leaves elliptic or ovate, 9–24 by 4–14 cm, glabrous except on midrib above; base broadly cuneate to rounded or slightly cordate; apex abruptly acute to acuminate; margins slightly undulate; secondary nerves 12–20 on each side, midrib flattened or slightly raised above; petioles 2–6 cm long, pubescent. Inflorescences 3–12 cm long, unbranched to singly branched; branchlets 2–7 cm long, bearing 3–5 flowers; flower buds ovoid, 1–2 cm long, shortly fine tomentose, subsessile. Calyx tubes ovoid, ca 1 cm long, 5-keeled; 2 longer lobes, 1–1.5 cm by 2–3 mm; 3 short lobes ca 5 mm long. Petals to ca 3 by 0.5–0.7 cm. Stamens ca 30; filaments 1–2 mm long; anthers 4–8 mm long, glabrous or sparsely pubescent at middle; connective-appendages slender, to ca 5 mm long. Ovary ca 5 by 4 mm; style 0.7–1 cm long. Nut ovoid, 2.5–4 by 1–2.5 cm including calyx tube; calyx tube 5-winged, wings 0.5–1 cm wide, sparsely pubescent; 2 longer lobes 7–13 by 2–2.5 cm; 3 smaller lobes ca 1–1.5 by 1 cm, revolute; fruit pedicels 1–2 mm long.

Thailand : NORTHERN: Chiang Mai, Chiang Rai, Phayao, Kamphaeng Phet, Nakhon Sawan; NORTH-EASTERN: Loei, Sakon Nakhon, Mukdahan; EASTERN: Nakhon Ratchasima, Si Sa Ket, Ubon Ratchathani; SOUTH-WESTERN: Uthai Thani, Kanchanaburi, Ratchaburi, Prachuap Khiri Khan; CENTRAL: Ang Thong, Saraburi; SOUTH-EASTERN: Sa Kaeo, Prachin Buri, Chon Buri (Si Racha), Rayong, Chanthaburi, Trat; PENINSULAR: Chumphon, Ranong, Surat Thani, Nakhon Si Thammarat, Phatthalung, Trang, Songkhla.

Distribution : India, Andaman Islands, Sri Lanka, Bangladesh (type), Myanmar, Laos, Cambodia, S Vietnam, the Philippines.

Ecology : Dry evergreen to evergreen forests, usually found by streams and river banks, occasionally found in dry evergreen forests near the beaches, to 500 m alt. Flowering: January–February; fruiting: May–July.

Vernacular : Yang na (ยางนา); yang khao (ยางขาว) yang mae nam (ยางแม่น้ำ), yang yuak (ยางหยวก)(Northern); yang khwai (ยางควาย)(Nong Khai); yang kung (ยางกุง)(Loei); ka-tin (กาตีล), cha-tian (จะเตียล)(Khmer); yang noen (ยางเนิน)(Chanthaburi); yang tai (ยางใต้)(Rayong); chan na (ชันนา), yang tang (ยางตัง)(Chumphon); yang hi (ยางฮี้)(Northern); yang nam man (ยางน้ำมัน)(Surat Thani); yang na khao (ยางนาขาว), yang tang (ยางตั่ง)(Chumphon, Prachuap Khiri Khan).

Notes: Dipterocarpus alatus × D. chartaceus can be found in east coast peninsular Thailand (Maxwell 85-335, Pooma et al. 2066, 2070, 2097, all in BKF). Putative hybrid D. alatus × D. costatus can also be found in Phuket (Beusekom & Phengklai 620 -AAU).