Plant material
Seventy-six herbarium specimens identified as D. communis or D. orientalis were used to obtain genomic, spatial, and morphometric data. They were selected as being representative of the macromorphological diversity and geographical distribution ranges of the two species as currently circumscribed (Supplementary Data Table S1). The genomic sampling also included material that were used as outgroup taxa, comprising the two species from the Borderea clade (D. chouardii and D. pyrenaica ), which is sister to the Tamus clade (Viruel et al ., 2016), and two members of the more distantly related African clade (D. elephantipes (L’Hér.) Engl. and D. sylvatica Eckl.).