Paraphyly of Paederieae, recognition of Putorieae and expansion of Plocama (Rubiaceae-Rubioideae)

Phylogenctic analyses of taxa that have been included in the tribe Paederieae are performed on the basis of a molecular dataset of plastid DNA sequences (the rbcL gene, rps16 intron, and the regions trnT-F). The paraphyly of Paederieae as currently circumscribed is confirmed. A clade comprising Paederia, Spermadietyon, Leptodermis, and Serissa is retrieved and the circumscription of Paederieae is proposed to be restricted to this clade. Paederia is sister to a clade with Spermadiclyon, Leptodermis, and Serissa. Paederia is subdivided into an Asian and an African clade, and within the African clade seven species endemic to Madagascar are sister to P. pospischilii in north-eastern Africa. The position of Kelloggia as sister to Rubieae is confirmed and a position of Saprosma in the Spermacoceae alliance is supported. The genera Putoria, Gaillonia (with segregates), Plocama, and Aitchisonia form a clade that is sister to Theligoneae/Ke//oggia/Rubieae. The name Putoricae is resurrected for the members of this clade. A synopsis of Putorieae is provided, where all species are placed in an expanded Plocama with 34 species. Thirty-one new combinations in Plocama are proposed. Plocama pendula on the Canary Islands is strongly supported as sister to a clade with P. crocyllis (former Crocyllis) in southern Africa and P. yemenensis and P. tinctoria (former Gaillonia) in southern Arabia/Horn of Africa.