Lithocarpus gracilis (Korth.) Soepadmo, Reinwardtia 8 (1970)
Latin for 'narrow or thin'.

Synonyms
Cyclobalanus diepenhorstii (Miq.) Oerst, Cyclobalanus gracilis (Korth.) Oerst, Lithocarpus cyathiformis A.Camus, Lithocarpus cyrtorhyncha (Miq.) Rehd., Lithocarpus diepenhorstii (Miq.) Barnett, Pasania cyrtorhyncha (Miq.) Gamble, Quercus cyrtorhyncha Miq., Quercus diepenhorstii Miq., Quercus gracilis Korth., Synaedrys cyrtorhyncha (miq.) Koidz, Synaedrys diepenhortsii (Miq.) Koidz

Description
Mid-canopy tree up to 39 m tall and 77 cm dbh. Stipules ca. 3 mm long. Leaves alternate, simple, penni-veined, glabrous, venation inconspicuous. Flowers ca. 3 mm diameter, green-yellow, placed in racemes. Fruits ca. 20 mm diameter, greenish, nut with basal cupule.

Ecology
In undisturbed mixed dipterocarp, coastal, keranga and sub-montane forests up to 1700 m altitude. Usually on hillsides and ridges with shallow sandy to clay soils. In secondary forests usually present as a pre-disturbance remnant tree.

Distribution
Peninsular Malaysia, Sumatra, Borneo (Sarawak, Sabah, East-Kalimantan).

Local names in Borneo
Empeli, Empenit, Empenin, Empili, Mempening, Tekaled vak.