Aichryson

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Aichryson

Scientific classification

Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Saxifragales
Family:	Crassulaceae
Genus:	Aichryson Webb & Berthel.

Species

About 15; see text

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.

[edit] Species

Aichryson bethencourtianum
Aichryson bollei
Aichryson divaricatum
Aichryson laxum
Aichryson palmense
Aichryson porphyrogennetos
Aichryson tortuosum (Gouty Houseleek)
Aichryson villosum

Other Species Recognized by Nyffeler in Eggli 2004

Aichryson brevipetalum
Aichryson dumosum
Aichryson pachycaulon (five subspecies have been recognized)
Aichryson parlatorei
Aichryson punctatum

Recently named species

Aichryson bitumosum

Relationships

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 realted to the three Canary Island genera. [see Ham and 't Hart (1998) American Journal of Botany 85: 123-134; Mort et al. (2001) American Journal of Botany 88: 76-91; Mes and 't Hart (1996) Molecular Ecology 5: 351-363; Mort et al. (2002) Systematic Botany 27: 271-288]

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 Evolution248: 71-83]. They found that the five subspeies of A. pachycaulon were not each others closest relatives (monophyletic) and additional species may need to be erected after additional study.