A new dry forest species, Phyllarthron arenicola (Bignoniaceae: Coleeae), from North-Western Madagascar

Summary Phyllarthron is a genus of large trees and shrubs with 18 currently recognised Malagasy species and one further species restricted to the Comoro Archipelago ( P. comorense DC.). Most of the species occur in sub-humid and humid parts of Madagascar, with only five currently recognised species in dry and semi-arid zones. The species newly described here occurs in dry shrubby vegetation on white sand. The number, shape and relative proportions of the leaf articles, and the presence of pubescence on the leaves, fruit, flower and the young shoots immediately distinguishes this species from others in the genus.