Fig. 4From: Diversification into novel habitats in the Africa clade of Dioscorea (Dioscoreaceae): erect habit and elephant’s foot tubersBeast chronogram of the African yam lineages dated using three calibrations points (● Dioscoreaceae: 80 mya [42], ★Dioscorea Stenophora clade crown node 48.2 mya [43] and Dioscorea dregeana - D. dumetorum clade node in Counpound Leaved clade 27.2 mya [44]). Only the four major clades are displayed in the figure. For subclade information, refer to Fig. 3 Back to article page