* Nyffeler, R. 2007. The closest relatives of cacti: insights from phylogenetic analyses of chloroplast and mitochondrial sequences with special emphasis on relationships in the tribe Anacampseroteae. American Journal of Botany. 94: 89-101.
* Stevens, P.F. 2001 (onwards). Angiosperm Phylogeny Website. Version 6, May 2005. 
The plants are spiny succulent shrubs and trees from 2-20 m tall, with thick water-storing stems and leaves that are deciduous in the long dry season. Some species build a distinct youth form as small procumbent shrub before a dominant stem is produced.
All species are dioecious (Decaria female-dioecious). The leaves, produced from areoles like in cacti, are small, appear single or in pairs and are accompanied by conical spines. The flowers are unisexual (except from Decaria) and radial symmetric.
The family is sometimes included within the Portulacaceae, but is treated as distinct by the Angiosperm Phylogeny Group. It is also closely related to the New World family Cactaceae (cacti), sufficiently closely so that the species of Didiereaceae can be grafted successfully on some cacti.
Key to the genera
Genera and species
Alluaudia (Drake) Drake 1903
* Alluaudia ascendens (Drake) Drake 1903
Alluaudiopsis Humbert & Choux 1934
* Alluaudiopsis fiherensis Humbert & Choux 1934
Decaria Choux 1929
* Decaria madagascariensis Choux 1929
* Didierea madagascariensis Baillon 1880
Several of the species are grown as indoor ornamental plants in specialist succulent collections.
* Eggli, Urs (Ed.): Sukkulentenlexikon Band 2: Zweikeimblättrige Pflanzen (Dicotyledonen) Eugen Ulmer Verlag, Germany 2002. ISBN 3-8001-3915-4
Source: Wikipedia, Wikispecies: All text is available under the terms of the GNU Free Documentation License