Cratoxylum formosum (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Cratoxylum formosum (Jack) Dyer

Protologue: Hook.f., Fl. Brit. India 1: 258 (1874).

Synonyms

Tridesmis ochnoides Spach (1836), Tridesmis formosa (Jack) Korth. (1843), Cratoxylum pentadelphum Turcz. (1863).

Vernacular names

• Brunei: pelawan
• Indonesia: kemutul (Sumatra), mulun, kasat baku (Kalimantan)
• Malaysia: derum (Peninsular), geronggang biabas (Sabah), entemu (Sarawak)
• Philippines: salinggogon (general, Pilipino), mango-gong, marangguub (Palawan)
• Laos: tiou-tiou 'som-som
• Thailand: tiu khao (Bangkok), tiu som (Nakhon Ratchasima), muu-to (peninsular)
• Vietnam: thành ngạnh dẹp.

Distribution

Burma, southern China, southern Vietnam, Cambodia, southern Thailand, Peninsular Malaysia, Sumatra, Java, Borneo, Sulawesi and the Philippines.

Uses

The timber is used as derum; the wood is also used for firewood and charcoal. C. formosum is sometimes planted as an ornamental.

Observations

A medium-sized to large tree of up to 45 m tall, bole slightly fluted and spiny at base, up to 65 cm in diameter, bark surface papery scaly, grey-brown to red-brown or purplish, inner bark yellow to yellow-brown; leaves elliptical or lanceolate to ovate or obovate, 3-17 cm × 1-8 cm, with an acute or shortly acuminate to rounded apex, sometimes glaucous beneath; inflorescence consisting of small 1-6-flowered cymes in the lower axils of shoots or apparently axillary on older branches; flowers heterodistylous, petals white or pink to red or rarely purplish, with an entire nectary scale at base; seeds (7-)12-17 per locule, unilaterally winged. C. formosum occurs in primary to old secondary forest and sometimes in savanna, along streams, along mangrove swamps, in peat-swamp forest and on hill slopes on sand or clay soils up to 600(-1200) m altitude. It is divided into two subspecies: subsp. pruniflorum (Kurz) Gogelein (synonym: C. pruniflorum Kurz) occurs in mainland South-East Asia and differs from subsp. formosum in having pubescent twigs, pedicels and calyces. The density of the wood is 700-1050 kg/m³at 15% moisture content. See also the table on wood properties.

Selected sources

33, 61, 89, 100, 146, 175, 276, 422, 430, 512, 748, 779, 789, 807.