''Aichryson'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of about 15 species of succulent, subtropical plants, mostly native to the

Canary Islands The Canary Islands (; es, Canarias, ), also known informally as the Canaries, are a Spanish autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to the African mainland, they are west of Morocc ...

, with a few in the

Azores ) , motto =( en, "Rather die free than subjected in peace") , anthem= ( en, "Anthem of the Azores") , image_map=Locator_map_of_Azores_in_EU.svg , map_alt=Location of the Azores within the European Union , map_caption=Location of the Azores wi ...

Madeira ) , anthem = ( en, "Anthem of the Autonomous Region of Madeira") , song_type = Regional anthem , image_map=EU-Portugal_with_Madeira_circled.svg , map_alt=Location of Madeira , map_caption=Location of Madeira , subdivision_type=Sovereign st ...

and

Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to ...

. The species of ''Aichryson'' are not frost-resistant. They are related to ''

Sempervivum ''Sempervivum'' (Brit. , U.S. �sɛ̃mpeɹ'vivũm is a genus of about 40 species of flowering plants in the family Crassulaceae, commonly known as houseleeks. Other common names include liveforever (the source of the taxonomical designation ''Sem ...

Jovibarba ''Jovibarba'' ("beard of Jupiter") is a small genus of three species of succulent flowering plants in the family Crassulaceae, endemic to mountainous regions in the southeastern quadrant of Europe. The genus is sometimes classified as a subgenu ...

Greenovia ''Aeonium'', the tree houseleeks, is a genus of about 35 species of succulent, subtropics, subtropical plants of the family (biology), family Crassulaceae. Many species are popular in horticulture. The genus name comes from the ancient Greek α� ...

Aeonium ''Aeonium'', the tree houseleeks, is a genus of about 35 species of succulent, subtropical plants of the family Crassulaceae. Many species are popular in horticulture. The genus name comes from the ancient Greek αἰώνιος / aiōnios (agel ...

'' and ''

Monanthes ''Monanthes'' is a genus of small, succulent, subtropical plants of the family Crassulaceae. The about ten species are mostly endemic to the Canary Islands and Savage Islands, with some found on Madeira. Its center of diversity is Tenerife, with ...

'', 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 A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, ...

''Aichryson'' × ''aizoides'' var. ''domesticum'' 'Variegatum' is a recipient of the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nort ...

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. History The Award of Garden Merit ...

Taxonomy

Recent phylogenetic studies of Crassulaceae indicate that ''Aichryson'' is closely related to ''

'' and ''

'' (both genera are also largely endemic to the Canary Islands). Two other genera of Crassulaceae that have many-parted (polymerous) flowers (''

'' and ''

'') are not closely related to the three Canary Island genera.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 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

* '' 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 are: * '' Aichryson brevipetalum'' * '' Aichryson dumosum'' * '' Aichryson pachycaulon'' (five subspecies have been recognized) * '' Aichryson parlatorei'' * '' Aichryson punctatum'' Recently named species include: * '' Aichryson bitumosum'' * '' Aichryson santamariensis''

References

Crassulaceae genera Flora of Macaronesia Succulent plants {{Crassulaceae-stub