Burseraceae

Dioecious, rarely monoecious trees or shrubs. Bark of twigs with a whorl of resiniferous ducts, bordered on the outer side by a distinct, closed or more or less interrupted sinuous sclerenchymatic cylinder. Pith of the twigs, petioles and petiolules not rarely with vascular strands, those in the twigs mostly amphivasal with mainly sclerenchymatic xylem, those in the petioles and petiolules collateral and consisting of abundant phloem, the strands predominantly reduced to mere vestigial resiniferous ducts. Leaves imparipinnate, sometimes 1-foliolate; spirally arranged, very rarely in pseudowhorls, usually more or less crowded at the ends of the branchlets. Stipules absent, Garuga and Canarium excepted (see Morph.); in addition in Garuga stipellas are often present (fig. 6a). Inflorescences paniculate, if poor tending towards racemes or spikes ( Canarium), axillary, often crowded at the ends of the branchlets, sometimes pseudoterminal (the subtending leaves or bracts early caducous), or terminal (apparently by suppression of the terminal bud). Bracts and bracteoles usually deltoid to subulate, in Canarium subg. Canarium often ovate to orbicular (see Morph.). Flowers 3—5-merous, generally greenish to creamy, usually unisexual (in Malaysia only Garuga excepted) with remains of the other sex, the androecium in ♀ flowers always only slightly reduced, the gynaecium in ♂ ones very slightly to entirely reduced. Sepals valvate, mostly connate. Petals in Mal. spp. free, induplicate-valvate, in the central part sometimes (especially Canarium) irregularly imbricate. Stamens usually twice as many as the petals, 1-whorled or indistinctly 2-whorled (in Triomma and a very few Santirias and Canariums as many as petals); filaments free or more or less united, not rarely adnate to the disk; anthers usually dorsifixed near the base (adnate in Santiria sect. Icicopsis), dehiscing lengthwise, introrse. Disk intrastaminal, Triomma excepted, variable in size and shape, in ♂ Canarium flowers often either consolidated with the remains of the pistil (ovariodisk), or replacing the latter, though usually still provided with a narrow central canal (fig. 20). Ovary usually isomerous, rarely meiomerous, each cell with 2 axile, epitropous, descending ovules; style simple, stigma globular, often slightly lobed. Fruits (in Mal. spp.) drupaceous with non-dehiscent, fleshy pericarp (in Haplolobus dry, in Triomma woody and dehiscent) and crustaceous to papyraceous endocarp; cells 1-seeded, often partly reduced. Seed exalbuminous; cotyledons entire or not, fleshy, containing oil. Distr. About 16 genera and c. 550 spp. distributed through the tropics. The family is subdivided in 3 tribes: The Protieae (6 genera) are centred in Central and S. America, the exceptions being Garuga (SE. Asia to Melanesia) and a few species of Protium (Madagascar, the Mascarenes, and SE. Asia to New Guinea inclusive). The Bursereae (5 genera) are centred in Africa and continental S. Asia, with the exceptions of Triomma (W. Malaysia) and Bursera (Central and S. America). The Canarieae (5 genera: Dacryodes, Santiria, Haplolobus, Scutinanthe, and Canarium) are nearly exclusively palaeotropical (Dacryodes sect. Dacryodes, comprising 2 spp. in Central and S. America), and especially Malaysian; a small number of species (in Dacryodes, Santiria, and Canarium) is African and very few, mainly Malaysian species, occur in Australia and the SW. Pacific Islands.