Leucaena leucocephala

A small tree, commonly reaching 3-15 m tall and 10-35 cm in bole diameter;and older trees may reach 20 m tall and 50 cm in diameter. Form varies from shrubby and highly branched in subsp. leucocephala to arborescent with a short clear bole to 5 m, upright angular branching and an open, rounded crown in subsp. glabrata. Bark is mid grey-brown with shallow rusty orange-brown vertical fissures;slash reddish. Leaves bipinnate with 4-9 pairs of pinnae per leaf and 13-21 pairs of leaflets per pinna. The leaflets are small, 9-21 mm long, 2-4.5 mm wide, linear-oblong or weakly elliptic, acute at the tip, rounded to obtuse at the base and glabrous except on margins, with a concave, cup-shaped, elliptic petiole gland. Flowers arranged on compact globose heads, the flower heads in groups of 2-6 in leaf axils arising on actively growing young shoots, the leaves developing simultaneously with the flowers, the heads 12-21 mm in diameter with 100-180 flowers per head, the flowers white. Hairy anthers (visible with a hand lens) distinguish Leucaena from all other mimosoid legume genera. Pods are 9-19 cm long, 13-21 mm wide, linear-oblong and flat with papery pod walls, mid- to orange-brown, glabrous and slightly lustrous (subsp. glabrata and subsp. ixtahuacana), or densely covered in white velvety hairs (subsp. leucocephala), arranged in clusters of 3-20, and occasionally up to 45, per flower head.