Currently under revision by E. Fischer (Koblenz) and M.E. Rahelivolonona (Antananarivo), numerous new species are currently in press. Within this large genus 3 groups are recognised: the spurless "Trimorphopetalum"; broad spurred "Humblotianae" and narrow-spurred "Vulgare". It is anticipated that the total no. of spp. will exceed 200.