Irvingia malayana Oliv. ex Benn., in Hook.f., Fl. Br. Ind. 1 (1875)

Synonyms
Irvingella harmandiana van Tiegh.
Irvingella malayana (Oliv. ex Benn.) van Tiegh.
Irvingella oliveri (Pierre) van Tiegh.
Irvingia harmandiana (van Tiegh.) Pierre
Irvingia longipedicellata Gagnep.
Irvingia oliveri Pierre

Diagnostics
Emergent tree up to 60 m tall and 117(-150) cm dbh. Stipules up to 30 mm long, dropped early. Leaves alternate, simple, penni-veined, glabrous, often with cordate leaf base. Flowers ca. 6 mm diameter, white-yellow, placed in panicles. Fruits ca. 46 mm long, green-yellow, drupes.

Description
More or less deciduous large tree, up to 60 m and 1.5 m diameter; bole straight with very prominent, thin, steep buttresses; bark grey, sometimes peeling off in large pieces. Leaves elliptic-oblong to lanceolate, slightly acuminate, broad-cuneate to roundish, or even subcordate at the base, distinctly prominent-reticulate-veined at either side, 8-20 by 2.5-9 cm; petiole 1-2 cm. Stipules surrounding the buds as a sharp, narrow-conical cap up to 3(-4) cm long. Panicles 5-15 cm long. Bracts ovate, acute, c. 1.5 mm. Pedicels up to 3(-5) mm, articulate at the base. Flowers glabrous, greenish-white or yellowish. Calyx 1.5 mm long, the lobes rounded, with membranous margin, c. 0.7 by 1 mm. Petals elliptic-oblong, rounded, finely reticulate, c. 3-4 by 2 mm, spreading finally or reflexed and with often involute margin in the upper half. Disk plicate outside and with sinuous margin, apex excavated in the middle. Filaments sinuous in bud, 3-6 mm, their base situated in the concavities of the disk; anthers c. 0.5 by 0.5 mm. Ovary c. 1 mm high, style 1-2 mm, sinuous in bud. Drupe with thick, fleshy, very fibrous, orange exocarp and hard endocarp, somewhat flattened ellipsoid, up to 6 by 4 cm when dry. Seed with small albumen, only at the back of the cotyledons. [from Flora Malesiana]

Ecology
In undisturbed mixed dipterocarp forests up to 600 m altitude. Usually on hillsides and ridges with clay to sandy soils.

Uses
The wood is used for knife handles and furniture. The seeds are edible and also used to extract fat for soap, wax and candles.

Distribution
Indo-China, Thailand, Peninsular Malaysia, Sumatra, Borneo.

Local names
Borneo: Asem pau, Batu, Euselu, Kayu batu, Kayu tulang, Kayu tulung, Kerangi, Melenna gunung, Patok entilit, Pau kijang, Tengilan.
Malaysia: bunga paukijang, kebayang, merelang, mirlang, pauh kijang.
Sumatra: emplas batu, kulut, pauh bayan, pauh kijang, pauh rusu, sepah bougin, sepah bungin, kalek, karsik, kaju bongin, sepah, pauh mente.