A new infrageneric classification for Mesembryanthemum (Aizoaceae: Mesembryanthemoideae)

Abstract

We present a new infrageneric classification for Mesembryanthemum L. (Aizoaceae: Mesembryanthemoideae), based on a phylogeny of the genus published in 2007. We re-affirm that a broad generic circumscription for Mesembryanthemum (including all 103 species of  the Mesembryanthemoideae) is the only group in the subfamily that can be recognized unambiguously by synapomorphies. We divide Mesembryanthemum into five subgenera, of which two are new: M. subg. Mesembryanthemum, M. subg. Cryophytum (N.E. Br.)  Bittrich, M. subg. Opophytum (N.E. Br.) Bittrich, M. subg. Phyllobolus (N.E. Br.) Klak and M. subg. Volkeranthus (Gerbaulet) Klak.  Furthermore, we recognize five sections in subg. Mesembryanthemum, six sections in subg. Phyllobolus and two sections in M. subg. Cryophytum. Descriptions and keys to all infrageneric taxa are provided.