Cratoxylum formosum (Jack) Benth. & Hook.f. ex Dyer, in Hook.f. Fl. Br. Ind. 1: 258 (1874)

Synonyms
Cratoxylum pentadelphum Turcz.
Cratoxylum prunifolium Dyer
Elodea formosa Jack
Tridesmis formosa (Jack) Korth.
Tridesmis jackii Spach
Tridesmis ochnoides Spach

Diagnostics
Sub-canopy tree up to 35 m tall and 39 cm dbh. Stem spiny at base, with brownish-red watery sap. Twigs with spines. Leaves deciduous, opposite, simple, penni-veined, secondary veins not uniting into intra- marginal vein, although they are looping, glabrous, whitish below. Flowers ca. 15 mm diameter, pink-purple, placed in bundles, petals with nectory glands. Fruits ca. 15 mm long, green-yellow-brown, dehiscent capsules filled with many flat winged seeds.

Description
Tree to 35 m tall, deciduous, glabrous, or partly pubescent; trunk spiny at base, bark grey, coarsely fissured, scaly; young shoots glabrous or pubescent, usually spiny, with interpetiolar scar interrupted. Leaves with petiole 5-15 mm, 3.5-14 by 1-7 cm, elliptic or sometimes obovatc to oblong or lanceolate or ovate, apex acute or shortly acuminate to rounded, base broadly cuneate to rounded, herbaceous to chartaccous, sometimes glaucous beneath. Inflorescence of 1-6-flowered cymules in lower axils of current shoots or, if shoot fails to develop, apparently axillary on older stems; pedicels 3-10(-15) mm. Flowers heterodistylous. Sepals 4-7 by 2-4 mm. Petals white or pink to red or (very rarely) purplish, 7-17 by 3-7 mm; nectary scale 2-4 mm, rounded, entire or subentire. Stamen fascicles 5-l4 mm, with stamens relatively lax, 20 per fascicle; anther gland present, purple, or absent. Staminodial fascicles (if well developed) orange-red, trigonous, linguiform, attenuate to truncate, not cucullate. Ovary 2-4.5 mm long; styles 2-8 mm. Capsule 10-16 by 4-6 mm, three times as long as sepals, ellipsoid, with columella half as long as capsule. Seeds (7-)12-17 per loculus, 6-7.5 by 2-4 mm, oblanceolate.

Ecology
In undisturbed mixed dipterocarp to secondary forest, keranga, (peat)-swamp, mangrove and coastal forests up to 600(-1200) m altitude. Mostly on alluvial sites, but also on hillsides and ridges. On sandy to ultrabasic soils.

Uses
Wood used for indoor construction and charcoal production. Bark can be used as brown coloured dye, wood is very hard and durable. The young shoots are edible and used as a raw vegetable.

Distribution
Hainan, Indo-China, Andaman Islands, Peninsular Malaysia, Sumatra, Java, Borneo, Philippines, Celebes.

Local names
Borneo: Biabas tahun, Butun, Dat tetong, Entemu, Geronggang, Geronggang derum, Kajo jelan, Kalambunan, Kasat baku, Mampat, Melan, Mangkutan, Mirinos, Mulun, Nyalin bahe, Obah bukit, Patok tilan, Pelawan, Raja tugag, Sarungan, Sidodot.
China: yue nan huang niu mu.
Java: rembang putun.
Laos: Mai tiw.
Malaysia: derom (Kedah, K. Lumpur), betina, gerunggang, mumpat (Perak), kemuntong, mampat (Kelantan), mampat (K. Lumpur), drum (P. Penang).
Philippines: mango-gong, marangguub, salingagon (Palawan).
Sumatra: kebutul, kemutul (Lampong), kembutul, tembutun (Palembang), mampat (Palembang, Riouw), ampet, mampet, temutun (Banka).
Thailand: Phak tiu.
Vietnam: Thanh nganh dep, Thanh nganh vang.