Shorea guiso (Blanco) Bl., Mus. Botl Lugd. Bat. 2 (1852)

Named after a Philippine local name for this species (Giso).

Synonyms
Anisoptera guiso DC
Dipterocarpus guiso Blanco
Euphoria malaanonan Blanco
Isoptera burckii Boerl.
Mocanera guiso Blanco
Shorea longipetala Foxw.
Shorea obtusa var. kohchangensis Heim
Shorea pierrei Hance
Shorea robusta var. schmidtii Heim
Shorea vidaliana Brandis
Shorea vulgaris Pierre ex Lanessan

Diagnostics
Emergent tree up to 73 m tall and 112 cm dbh. Stem with resin. Stipules up to ca. 7 mm long. Leaves alternate, simple, penni-veined, glabrous, secondary veins close together. Flowers ca. 10 mm in diameter, yellow-red, placed in panicles. Fruits ca. 8 mm long, green-red, with three ca. 55 mm long wings, wind dispersed.

Description
Large buttressed tree. Young parts at first greyish buff pubescent, early caducous except on inflorescence, calyx, corolla outside, ovary and nut; twig apices and stipule outside densely so at first, becoming sparse as parts expand, remaining dense on inflorescence and nut. Twig. c. 1 mm diameter apically. slender, smooth, with minute inconspicuous stipule scars. Bud to 5 by 3 mm, compressed, ovate-falcate. Stipule to 7 by 5 mm, oblong, subacute, caducous. Leaves 5.5-14 by 2.5-6 cm, oblong-lanceolate, thinly coriaceous, glabrescent; base obtuse to broadly cuneate, acumen to 1 cm long, prominent, broad; nerves (11-)15-19 pairs, slender, at 45-55 degrees to the midrib but up to 90 degrees at the base; tertiary nerves very slender, densely scalariform, frequently obscure; midrib slender, raised beneath, evident but somewhat depressed above; petiole 1-1.8 cm long, slender. Panicle to 10 cm long, slender, lax, pendent, the branchlets bearing to 5 secund flowers; bracts and bracteoles minute, linear, fugaceous. Flower bud to 1 cm long, slender. Sepals broadly ovate; outer 3 acute, inner 2 acuminate, with thin margins. Petals bright yellow-red at base within, narrowly lanceolate, densely pubescent on parts exposed in bud. Stamens 20-28; filaments lorate, tapering, glabrous; anthers narrowly oblong, glabrous, the two outer cells somewhat the larger; appendage c. 0.5 as long as anther, with 1-4(-8) long bristles. Ovary ovoid-conical, densely pubescent, surmounted by a columnar glabrous style c. 0.5 its length, 3 longer fruit calyx lobes to 5.5 by 1 cm, spatulate, obtuse, c. 3 mm broad above the to 8 by 5 mm saccate thickened base; 2 shorter lobes to 3 cm long, linear but similar at base. Nut to 8 by 5 mm, ovoid, apiculate, hidden by base of calyx lobes. [from Flora Malesiana]

Ecology
In undisturbed forests up to 400 m altitude. Usually on ridges with sandy and limestone soils. Scattered in lowland forest on red soils, most common in slightly seasonal climates.

Uses
The timber is used. The hard red timber is valuable for light construction in the Philippines.

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

Local names
Borneo: Ambam, Damar kenuar batu, Hibi, Keping burung, Lauan, Lempong, Majau, Membatu, Menkabang, Oba suluk, Pakulin batu, Pelapak, Raru, Selangan batu, Selangan batu merah.
Malaysia: Membatu, Merbatu, Lemesa, Lemesa kulor, Lemesa nerang, Chengal pasir, Meranti bulu, Meranti pahang, Resak samak, Selimbar.
Philippines: Guijo.
Sumatra: Beraja, Damar kenuar batu, Meranti hitam.