Cratoxylum sumatranum (Jack) Blume, Mus. Bot. Lugd. Bat. 2 (1852)

Synonyms
Ancistrolobus floribundus Turcz.
Ancistrolohus micradenius Turcz.
Cratoxylum arboreum Elmer
Cratoxylum blancoi Blume
Cratoxylum blancoi var. apiculatum Merr.
Cratoxylum celebicum Blume
Cratoxylum clandestinum Blume
Cratoxylum floribundum (Turcz.) Fern.-Vill.
Cratoxylum hornschuchii Blume
Cratoxylum hypericinum Merr.
Cratoxylum hypericum (Blume) Merr.
Cratoxylum punctulatum Elmer ex Merr. Cratoxylum racemosum Blume
Elodea sumatrana Jack
Hornschuchia hypericina Blume

Diagnostics
Emergent tree up to 51 m tall and 80 cm dbh. Stem with white to yellow latex. Leaves deciduous, opposite, simple, penni-veined, glabrous, venation conspicuous and not forming an intra-marginal vein. Inflorescens many flowered. Flowers ca. 8 mm diameter, pink-red-purple, placed in panicles, petals without nectary scale. Fruits ca. 8 mm long, yellow-brown-black, dehiscent capsules, filled with many small, unilaterally winged seeds.

Description
Tree or shrub, to 51 m tall and 80 cm diameter, deciduous to subdeciduous, glabrous; bark fissured, peeling in strips, dark brown; young shoots with interpetiolar scar continuous. Leaves sessile or with petiole up to 15 mm, 4-18 by 2-7 cm, elliptic to ovate-oblong, apex rounded to cuspidate, base subcordate or rounded to attenuate, herbaceous to chartaceous, sometimes glaucous beneath. Inflorescence a foliate panicle, often large; pedicels 1.5-5 mm. Flowers homostylous. Sepals 3-6.5 by 3-4.5 mm. Petals dark or brownish red to brick red, pale green at base, 4¡ª9 by 1.5-4mm. Stamen fascicles 2.5-7.5 mm long, with stamens +/- congested, c. 120 per fascicle; anther gland absent. Staminodial fascicles (if well developed) yellow, up to 3 mm long, flattened, oblong to obovate, cucullate. Ovary 1.5-3 mm long; styles 1.5-3 mm. Capsule 7-10 by 3-5 mm, c. 1-3 times as long as the sepals, cylindric, with columella basal to half as long as capsule. Seeds 3-10 per loculus, 5-7.5 by 1.5-2 mm, oblanceolate to oblong. [from Flora Malesiana]

Ecology
Often in disturbed open sites in mixed dipterocarp and scrub vegetations up to 800(-1200) m altitude. Most common on hillsides and ridges with clay to sandy soils, but also on limestone.

Uses
The plant's leaves and bark have medicinal uses. Its timber is suitable for light construction, furniture, carving, firewood and charcoal production.

Distribution
Burma, Indo-China, Thailand, Peninsular Malaysia, Sumatra, Java, Lesser Sunda Islands, Borneo, Philippines, Celebes.

Local names
Borneo: Irat, Geronggang, Laka-laka, Lingan, Mampat, Manding, Mentialing, Serungan, Serungan mampat.
Java: maron(g) (Salak), rinjung gide (Sund.), wuluan (Central Java).
Philippines: Kansilay, Lakansilay and Guyong-guyong.
Sulawesi: kaju arang, sisio pule (Malili).
Sumatra: garinggang (P. Simalur), garunggang, kemutun.