Aichryson

Aichryson is a genus of about 15 species of succulent, subtropical plants, mostly native to the Canary Islands, with a few in the Azores, Madeira and Morocco, and one in Portugal.
The species of "Aichryson" are not frost-resistant. They are related to "Sempervivum, Jovibarba, Greenovia, Aeonium" and "Monanthes", readily seen in their similar flowers.
The genus name comes from a contraction of the Greek "aei" (always) and "chrysos" (gold).
Several species are cultivated as ornamental plants. The hybrid cultivar "Aichryson" × "aizoides" var. "domesticum" 'Variegatum' is a recipient of the Royal Horticultural Society's Award of Garden Merit. 
Taxonomy.
Recent phylogenentic studies of Crassulaceae indicate that "Aichryson" is closely related to "Monanthes" and "Aeonium" (both genera are also largely endemic to the Canary Islands). Two other genera of Crassulaceae that have many-parted (polymerous) flowers ("Sempervivum" and "Jovibarba") are not closely related to the three Canary Island genera.
On the Canary Islands, the center of species diversity seems to be the island of La Palma.
Relationships within "Aichryson" were investigated by Fairfield et al. (2004) ["Plant Systematics and Evolution" 248: 71–83]. They found that the five subspecies of "A. pachycaulon" were not each other's closest relatives (monophyletic) and additional species may need to be erected after additional study.
Species.
Other species recognized by Nyffeler in Eggli 2004 are:
Recently named species include: