Phedimus


Phedimus is a genus of the succulent family Crassulaceae, with about 18 species, distributed in eastern Europe and Asia. The genus is described with two subgenera, but one of these is also recognized as a separate genus, Aizopsis. Phedimus kamtschaticus is widely grown as an ornamental ground cover and has gained the Royal Horticultural Society's Award of Garden Merit.

Description

Species are perennial or rarely annual herbs, usually glabrous stems, sometimes woody at base, from thin woody rhizome. Leaves decussate or alternate, with narrow base, and several hydathodes on lower face along margins. The flowering branches are erect or descending, with dense inflorescences exhibiting many flowered terminal pleiochasia. Flowers 4-7 parts, sepals usually unequal, petals free, usually spreading. The fruits are follicles, usually spreading and seeds costate-papillate, but multipapillate in Phedimus selskianus.
When treated as Phedimus ''sensu lato, i.e. including Aizopsis, subgenus Phedimus has creeping and rooting stems, flowers white, pink, red or purplish and chromosome numbers x=5,6,7, while subgenus Aizoon'' has annual shoots often woody at base, emerging from woody rhizomes, flowers yellow, orange or reddish and x=8.

Taxonomy

Phedimus is a genus in the family Crassulaceae, subfamily Sempervivoideae, tribe Umbiliceae, together with three other genera. It was segregated from the very large cosmopolitan and polyphyletic genus, Sedum, where it was variously considered a section or subgenus. Within the tribe it is a sister group to Aizopsis. There, it is distinguished by flower colouration, floral morphology, distribution and chromosome numbers. Some authors include Aizopsis as a subgenus:
Subgenus Phedimus, Mediterranean to Caucasus. Subgenus Aizoon China, Japan, Korea and central Siberia.