Aichryson

{{short description|Genus of flowering plants in the family Crassulaceae}} {{Automatic taxobox | image = Aichryson punctatum.jpg | image_caption = ''Aichryson punctatum'' | display_parents = 2 | taxon = Aichryson | authority = Webb & Berthel. | subdivision_ranks = Species | subdivision = 16; see text | synonyms = ''Macrobia'' {{small|(Webb & Berthel.) G.Kunkel}} | synonyms_ref = <ref name = powo>{{cite web |title=''Aichryson'' Webb & Berthel. |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:12121-1 |website=Plants of the World Online |publisher=Royal Botanic Gardens, Kew |access-date=18 February 2025}}</ref> }}

'''''Aichryson''''' is a genus of 16 species of succulent, subtropical plants, native to the Canary Islands, Azores, and Madeira.<ref name = powo/>

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).<ref name="Eggli Newton 2004">{{cite book |last=Eggli |first=Urs |last2=Newton |first2=Leonard E. |title=Etymological Dictionary of Succulent Plant Names |publisher=Springer |location=Berlin, Heidelberg |year=2004 |isbn=978-3-540-00489-9 |url=https://books.google.com/books?id=u2n5vusQ1DEC&pg=PA4 |access-date=11 November 2018 |page=4}}</ref>

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.<ref name = RHSPF>{{cite web | url = https://www.rhs.org.uk/Plants/272993/Aichryson-x-aizoides-var-domesticum-Variegatum-(v)/Details | title = ''Aichryson'' × ''aizoides'' var. ''domesticum'' 'Variegatum' | website = www.rhs.org | publisher = Royal Horticultural Society | accessdate = 27 February 2020}}</ref><ref>{{cite web | url = https://www.rhs.org.uk/plants/pdfs/agm-lists/agm-ornamentals.pdf | title = AGM Plants - Ornamental | date = November 2018 | page = 4 | publisher = Royal Horticultural Society | website = www.rhs.org | accessdate = 27 February 2020}}</ref>

==Taxonomy== Recent phylogenetic 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.<ref>Ham and 't Hart. (1998). ''American Journal of Botany'', 85: 123–134</ref><ref>Mort et al. (2001). ''American Journal of Botany'', 88: 76–91</ref><ref>Mes and 't Hart. (1996). ''Molecular Ecology'', 5: 351–363</ref><ref>Mort et al. (2002). ''Systematic Botany'', 27: 271–288</ref>

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== 16 species, and several naturally occurring interspecies hybrids, are accepted.<ref name = powo/> * ''Aichryson × aizoides'' {{small|(Lam.) E.C.Nelson}} * ''Aichryson × azuajei'' {{small|Bañares}} * ''Aichryson bitumosum'' {{small|Bañares}} * ''Aichryson bollei'' {{small|Webb ex Bolle}} * ''Aichryson × bramwellii'' {{small|G.Kunkel}} * ''Aichryson brevipetalum'' {{small|Praeger}} * ''Aichryson × buchii'' {{small|Bañares}} * ''Aichryson × cumbrense'' {{small|Bañares}} * ''Aichryson dichotomum'' {{small|(DC.) Webb & Berthel.}} * ''Aichryson divaricatum'' {{small|(Aiton) Praeger}} * ''Aichryson dumosum'' {{small|(Lowe) Praeger}} * ''Aichryson laxum'' {{small|(Haw.) Bramwell}} * ''Aichryson pachycaulon'' {{small|Bolle}} (five subspecies have been recognized) * ''Aichryson palmense'' {{small|Webb ex Bolle}} * ''Aichryson parlatorei'' {{small|Bolle}} * ''Aichryson porphyrogennetos'' {{small|Bolle}} * ''Aichryson × praegeri'' {{small|G.Kunkel}} * ''Aichryson punctatum'' {{small|(C.Sm. ex Link) Webb & Berthel.}} * ''Aichryson roseum'' {{small|Bañares}} * ''Aichryson santamariensis'' {{small|M.Moura, Carine & M.Seq.}} * ''Aichryson tortuosum'' {{small|(Aiton) Webb & Berthel.}} – gouty houseleek * ''Aichryson villosum'' {{small|(Aiton) Webb & Berthel.}}

==References== {{Reflist}}

Category:Aichryson Category:Crassulaceae genera Category:Endemic flora of Macaronesia Category:Succulent plants