Volume 13 > Part 4 > Year 2017 > Page 575 > Dipterocarpaceae > Dipterocarpus

5. Dipterocarpus costatus C.F.Gaertn.wfo-0000651315

Suppl. Carp.: 50, t. 187. 1805; Craib, Fl. Siam. 1: 133. 1925; Smitinand, Santisuk & Phengklai, Thai Forest Bull., Bot. 12: 33. 1980; P.S.Ashton, Fl. Males., Ser. 1, Spermat. 9: 321. 1982; Smitinand, J.E.Vidal & P.H.Hô, Fl. Cambodge, Laos & Vietnam 25: 37. t. 5, figs. 1–3. 1990; K.P.Janardhanan, Fl. India 3: 210. 1993; Svengs. & J.E.Vidal, Diptérocarp. Laos: 17. 1997; Pooma & M.F.Newman, Thai Forest Bull., Bot. 29: 124. 2001; Symington, P.S.Ashton & S.Appanah, Malayan Forest Rec. 16: 372. 2004; Poopath, Sookchaloem & Santisuk, Thai Forest Bull., Bot. 40: 64. 2012; Gardner, Sidisunthorn & Chayamarit, Forest Trees S. Thailand Vol. 1: 421, fig. 646. 2015. Plate XLV: 2

Accepted Name : This is currently accepted.

Synonyms & Citations :

Description : Tree to 40 m tall. Indumentum densely tufted tomentose on young twigs, buds, petioles, lower surface of leaves, especially on secondary nerves, inflorescences and calyx. Buds 0.8–1.5 cm long. Stipules enlarged to 10 cm long, red-pinkish. Leaves elliptic or slightly ovate, 6–20 by 2.5–12 cm, glabrous on upper surface except on midrib; base broadly cuneate to rounded-cordate; apex abruptly acute to acuminate; margins slightly crenate in upper half above; secondary nerves 10–18 on each side; midrib flattened or slightly sunk above; petioles 1–3 cm long. Inflorescences 2–6 cm long, unbranched or singly branched; branchlets bearing up to 7 flowers; flower buds lanceolate, 2–2.5 cm long; pedicels 1–2 mm long. Calyx tube 5-keeled, 0.7–1 by 0.5–0.6 cm; 2 longer lobes ca 1 by 0.2–0.3 cm; 3 short lobes ca 2 mm long. Petals 2.5–3 by 0.2–1 cm, shortly tomentose outside, sparsely so at apex inside. Stamens ca 30; filaments to ca 4 mm long; anthers 4–6 mm long; connective-appendages slightly shorter than the anthers. Ovary ca 3 mm in diam.; style 1–1.2 cm long. Nut ovoid to subglobose, 1–2 by 0.8–1.5 cm including calyx tube, densely to sparsely tomentose; calyx tube 5-keeled to narrowly 5-winged, wings 1–3 mm wide; 2 longer lobes 4–11 by 1.5–2.5, slightly revolute at base; 3 smaller lobes 0.5–1 by 0.5–0.7 cm, strongly revolute; fruit pedicels 1–2 mm long.

Thailand : NORTHERN: Chiang Mai, Lampang, Phrae, Uttaradit, Tak, Sukhothai; NORTH-EASTERN: Phetchabun, Nong Khai, Bueng Kan, Nakhon Phanom; EASTERN: Nakhon Ratchasima, Ubon Ratchathani; SOUTH-WESTERN: Kanchanaburi, Phetchaburi; CENTRAL: Nakhon Nayok; SOUTH-EASTERN: Sa Kaeo, Chanthaburi, Trat; PENINSULAR: Chumphon, Ranong, Surat Thani, Phangnga, Phuket, Krabi, Nakhon Si Thammarat, Trang, Satun, Yala, Narathiwat.

Distribution : Bangladesh (type), Andaman and Nicobar Islands, Myanmar, Indochina, Peninsular Malaysia.

Ecology : Evergreen forests, lowland, hillsides and ridges, to 1,300 m alt. Flowering: December–July; fruiting: January–December.

Vernacular : Yang pai (ยางปาย), yang phrai (ยางพราย)(Northern); yang krai (ยางกราย), yang kaen (ยางแกน), yang hi (ยางฮี, ยางฮี้), yang huak (ยางฮวก)(Northern); yang cho nam man (ยางเจาะน้ำมัน)(Ubon Ratchathani); yang daeng (ยางแดง)(Chanthaburi, Trat); ku wing (กูวิง)(Malay-Pattani); yang bai iat (ยางใบเอียด)(Nakhon Si Thammarat); yang hua waen (ยางหัวแหวน)(Satun); yang kra bueang (ยางกระเบื้อง)(Chumphon).

Notes: Dipterocarpus costatus × D. obtusifolius can be found in deciduous dipterocarp forest (Smitinand 4031; Ploenchit 1026, 3340; Pooma et al. 2341; all in BKF) and D. costatus × D. gracilis from Kanchanaburi (Phattarahirankanok & Chayamarit 86 -BKF).