About forgotten names in the genus Euphorbia L. (Euphorbiaceae) from Madagascar

Errors in the interpretation of some names in Malagasy Euphorbia L. (Euphorbiaceae) are corrected here. Euphorbia subapoda Baill., who was erroneously considered as a synonym of Euphorbia primulifolia Baker, is reinstated, with Euphorbia quartziticola Leandri as synonym. The identity of the poorly known Euphorbia physoclada is also elucidated following a better understanding of its type locality. A description and photographs are provided for the first time. At last, it is shown that Euphorbia francoisii Leandri is a synonym of Euphorbia decaryi Guillaumin and that the plant currently known as Euphorbia decaryi is in fact Euphorbia boiteaui Leandri. In consequence, new combinations are proposed for varieties described under Euphorbia francoisii and Euphorbia decaryi.