Crassulaceae [SEP] parent taxon
included Crassulaceae in Rosales, but newer schemes treat them in the order Saxifragales. Classification within the family is difficult because many of the species hybridize readily, both in the wild and in cultivation.
Six subfamilies of Crassulaceae were described by Berger in 1930: Crassuloideae, Kalanchiodeae, Cotyledonoideae, Sempervivoideae, Sedoideae, and Echeveroideae. Though various revisions since have proposed four, three, and two subfamilies, many botanists still use Berger's classification, although some of the subfamilies are polyphyletic.
Molecular phylogenetics has shown that morphological characters
region, though Africa is more widely recognized as the place of origin. Other sources suggest that Crassulaceae evolved approximately 70 million years ago together with families Penthoraceae and Haloragaceae. The taxon is considered to have a gradual evolution, whereas there is a basal split between Crassuloideae and the rest of the family. The Crassuloideae lineage migrated into Southern Africa and other genera within Sedoideae migrated to Europe, Asia, Northern and Central America.
Genera.
The genera listed below and division into subfamilies are based on APWeb .
External links