Alectryon macrococcus of the soapberry family (Sapindaceae) is a tree up to 11 m (36 ft) tall with reddish brown branches. The leaves are usually 20 to 55 cm (8 to 22 in) long, typically with two to five pairs of egg-shaped, slightly asymmetrical leaflets, each 10 to 28 cm (4 to 11 in) long and 4 to 12 cm (1.6 to 4.7 in) wide. Glossy and smooth above, the leaves have a conspicuous netted pattern of veins. A dense covering of rust-colored hairs persists on the lower surfaces of mature leaves of A. macrococcus var. auwahiensis, whereas the mature leaves of A. macrococcus var. macrococcus lack hairs or are only slightly hairy. In both varieties, the flowers, which may be either bisexual or male, are borne in branched clusters up to 30 cm (l2 in) long and lack petals. The hard, spherical fruit borne singly or sometimes in pairs, encloses a single glossy brown seed with a scarlet aril (fleshy covering over the seed).