Haplocoelum aurantium, Sapindaceae, a new tree species from submontane forest in Cameroon

Haplocoelum aurantium Burgt, Ngansop & Tchiengué, Sapindaceae, is described and illustrated. It is a tree, to 18 m high, with a stem to 50 cm diameter, often overhanging. On mature trees the leaves usually have 8–18 leaflets; 40% of leaves have 14 or 16 leaflets. 28% of leaves have an odd number of leaflets. The leaflets are opposite, sub-opposite, or alternate. The flowers are unknown. The fruits are indehiscent, orange and globular, 1.5–2.3 cm diameter. Haplocoelum aurantium occurs in submontane forest, at 700–1400 m elevation. The tree species is endemic to Cameroon, in parts of the Littoral Region, Southwest Region and West Region. Twelve herbarium collections have been made, in an area of 7500 km2. Haplocoelum aurantium is provisionally assessed as Vulnerable.