Brucea J.F.Mill.

Scientific Description

Family Simaroubaceae.

Habit and leaf form. Trees, or shrubs. Stem internodes solid. Mesophytic. Leaves alternate; spiral; petiolate; non-sheathing; not gland-dotted; compound; pinnate (imparipinnate); imparipinnate. Leaflets narrowly ovate, or ovate to oblong; oblique at the base. Leaf blades pinnately veined; cross-venulate. Leaves without stipules. Leaf blade margins serrate (each serration with an abaxial marginal gland at end of a lateral vein), or dentate. Leaves without a persistent basal meristem. Leaf anatomy. Hairs present (usually shortly hairy above and shortly and densely hairy below). Branched hairs absent. Extra-floral nectaries absent. Stem anatomy. Secondary thickening developing from a conventional cambial ring.

Reproductive type, pollination. Fertile flowers hermaphrodite, or functionally male, or functionally female, or functionally male and functionally female, or hermaphrodite, functionally male, and functionally female. Unisexual flowers present, or absent. Plants hermaphrodite, or monoecious, or dioecious, or polygamomonoecious. Female flowers with staminodes (small), or without staminodes. Male flowers with pistillodes.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in cymes. The terminal inflorescence unit cymose, or racemose. Inflorescences axillary; inflorescence cymose with raceme-like thyrses or small cymes in slender axillary spikes. Flowers pedicellate; bracteate; ebracteolate; small; regular; 4 merous; cyclic; when hermaphrodite, pentacyclic. Floral receptacle developing an androphore, or developing a gynophore, or with neither androphore nor gynophore. Free hypanthium absent. Hypogynous disk present; extrastaminal. Perianth with distinct calyx and corolla; 8; 2 -whorled; isomerous. Calyx present; 4; 1 -whorled; gamosepalous; imbricate, or valvate; regular. Calyx lobes ovate. Corolla present; 4; 1 -whorled; polypetalous; imbricate; regular; greenish white, or green to red, or green to purple. Petals oblong, or linear. Fertile stamens present, or absent (female flowers). Androecial members definite in number. Androecium 4. Androecial members free of the perianth; all equal; free of one another; 2 -whorled. Androecium exclusively of fertile stamens. Stamens 4; all more or less similar in shape; isomerous with the perianth; oppositisepalous. Filaments appendiculate, or not appendiculate. Anthers dorsifixed; versatile; dehiscing via longitudinal slits; introrse; tetrasporangiate. Fertile gynoecium present, or absent (male flowers). Gynoecium 4 carpelled. Carpels isomerous with the perianth. Gynoecium apocarpous, or syncarpous; semicarpous to synovarious, or synstylous; superior. Carpel (if semi- or apocarpous,) stylate; apically stigmatic, or with a lateral style, or with a gynobasic style. Gynoecium stylate. Styles 4. Ovules epitropous; hemianatropous to anatropous.

Fruit and seed features. Fruit scarcely fleshy; indehiscent.

Etymology. After James Bruce (1730–1794), a Scottish explorer of Africa.