{{Short description|Genus of succulents}} {{Automatic taxobox | image = Aeonium undulatum.JPG | image_caption = Saucer-plant (''Aeonium undulatum'') | display_parents = 2 | taxon = Aeonium | authority = Webb & Berthel. | subdivision_ranks = Species | subdivision = About 35, see text }}
'''''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 (ageless).<ref name="Eggli Newton 2004">{{cite book | last1 = Eggli | first1 = U. | last2 = Newton | first2 = L.E. | title = Etymological Dictionary of Succulent Plant Names | publisher = Springer Berlin Heidelberg | year = 2004 | isbn = 978-3-540-00489-9 | url = https://books.google.com/books?id=u2n5vusQ1DEC&pg=PA3 | access-date = 25 September 2018 | page = 3 }}</ref> While most of them are native to the Canary Islands, some are found in Madeira, Cape Verde, Morocco, in East Africa (Ethiopia, Somalia, Uganda, Tanzania and Kenya) and Yemen.
==Description== The succulent leaves are typically arranged on a basal stem, in a dense, spreading rosette. A feature which distinguishes this genus from many of its relatives is the manner in which the flowers bear free petals, and are divided into 6 or 12 sections. With the exception of ''Aeonium simsii'', each rosette produces a central inflorescence only once, and then dies back (though it will usually branch or offset to produce ensuing rosettes).
Low-growing ''Aeonium'' species are ''A. tabuliforme'' and ''A. smithii''; large species include ''A. arboreum and'' ''A. valverdense''. They are related to the genera ''Sempervivum'', ''Aichryson'' and ''Monanthes'', as can be seen by their similar flower and inflorescences. Recently,{{when|date=January 2023}} the genus ''Greenovia'' has been placed within ''Aeonium''.{{citation needed|date=January 2023}}
== Species and distribution == All but two species are native to at least one of three different Macaronesian archipelagos (the Canary Islands, Madeira, or Cape Verde). Most aeoniums are from the Canary Islands,<ref name="Bramwell2">{{cite book |last1=Bramwell |first1=D. |title=Wild flowers of the Canary Islands |last2=Bramwell |first2=Z. |publisher=Editorial Rueda |year=2001 |isbn=84-7207-129-4 |location=Madrid, Spain}}</ref><ref name="ICN2">{{cite web |title=International Crassulaceae Network: ''Aeonium'' |url=http://www.crassulaceae.ch/de/artikel?akID=22&aaID=2&aiID=A |access-date=19 February 2017 |publisher=International Crassulaceae Network}}</ref> The only species not native to these three Macaronesian island groups (''Aeonium stuessyi'' and ''Aeonium'' ''leucoblepharum'') are found in Ethiopia, Kenya and Tanzania; and Ethiopia, Kenya, Sudan, Uganda and Yemen, respectively. ''Aeonium arboreum'' is native to both the Canary Islands and Morocco.
Species accepted by Plants of the World Online as of April 2023:<ref name=POWO>{{cite web |url=http://www.plantsoftheworldonline.org/taxon/urn:lsid:ipni.org:names:12119-1 |title=''Aeonium'' Webb & Berthel. |date=2023 |website=Plants of the World Online |publisher=Royal Botanic Gardens, Kew|access-date=13 April 2023}}</ref> {| class="wikitable sortable" |+ !'''Species''' !'''Distribution''' !class=unsortable| |- |''Aeonium aizoon'' (Bolle) T.H.M.Mes |Canary Islands (Tenerife) |alt=Aeonium aizoon|thumb|none |- |''Aeonium appendiculatum'' Bañares |Canary Islands (La Gomera) |alt=Aeonium appendiculatum|thumb|none |- |''Aeonium arboreum'' (L.) Webb & Berthel. |Canary Islands (Gran Canaria, Tenerife, La Gomera, La Palma, El Hierro); Morocco |alt=Aeonium arboreum|thumb|none |- |''Aeonium aureum'' (C.Sm. ex Hornem.) T.H.M.Mes |Canary Islands (Gran Canaria, Tenerife) |alt=Aeonium aureum|thumb|none |- |''Aeonium balsamiferum'' Webb & Berthel. |Canary Islands (Lanzarote, Fuerteventura) |alt=Aeonium balsamiferum|thumb|none |- |''Aeonium canariense'' (L.) Webb & Berthel. |Canary Islands (Gran Canaria, Tenerife; La Gomera, La Palma, El Hierro) |alt=Aeonium canariense|thumb|none |- |''Aeonium castello-paivae'' Bolle |Canary Islands (La Gomera) |alt=Aeonium castello-paivae|thumb|none |- |''Aeonium ciliatum'' (Willd.) Webb & Berthel. |Canary Islands (Tenerife) |alt=Aeonium ciliatum|thumb|none |- |''Aeonium cuneatum'' Webb & Berthel. |Canary Islands (Tenerife) |alt=Aeonium cuneatum|thumb|none |- |''Aeonium davidbramwelii'' H.Y.Liu |Canary Islands (La Palma) |alt=Aeonium davidbramwelii|thumb|none |- |''Aeonium decorum'' Webb ex Bolle |Canary Islands (Tenerife, La Gomera) |alt=Aeonium decorum|thumb|none |- |''Aeonium dodrantale'' (Willd.) T.H.M.Mes |Canary Islands (Tenerife) |alt=Aeonium dodrantale|thumb|none |- |''Aeonium glandulosum'' (Aiton) Webb & Berthel. |Maderia (Madeira, Desertas, Porto Santo) |alt=Aeonium glandulosum|thumb|none |- |''Aeonium glutinosum'' (Aiton) Webb & Berthel. |Madeira (Madeira, Desertas) |alt=Aeonium glutinosum|thumb|none |- |''Aeonium gomerense'' (Praeger) Praeger |Canary Islands (La Gomera) |alt=Aeonium gomerense|thumb|none |- |''Aeonium goochiae'' (Christ.) Praeger |Canary Islands (La Palma) |alt=Aeonium goochiae|thumb|none |- |''Aeonium gorgoneum'' J. A. Schmidt |Cabo Verde (Santo Antão, São Nicolau, São Vicente) |alt=Aeonium gorgoneum|thumb|none |- |''Aeonium haworthii'' (Salm-Dyck ex Webb & Berthel.) Webb & Berthel. |Canary Islands (Tenerife) |alt=Aeonium haworthii|thumb|none |- |''Aeonium hierrense'' (R. P. Murray) Pit. & Proust. |Canary Islands (La Palma, El Hierro) |alt=Aeonium hierrense|thumb|none |- |''Aeonium lancerottense'' (Praeger) Praeger |Canary Islands (Lanzarote) |alt=Aeonium lancerottense|thumb|none |- |''Aeonium leucoblepharum'' Webb ex A. Richard |Yemen, Ethiopia, Sudan, Kenya, Uganda |alt=Aeonium leucoblepharum|thumb|none |- |''Aeonium lindleyi'' Webb & Berthel. |Canary Islands (Tenerife) |alt=Aeonium lindleyi|thumb|none |- |''Aeonium liui'' Arango |Canary Islands (Tenerife) | |- |''Aeonium nobile'' (Praeger) Praeger |Canary Islands (La Palma) |alt=Aeonium nobile|thumb|none |- |''Aeonium percarneum'' (R. P. Murray) Pit. & Proust. |Canary Islands (Gran Canaria) |alt=Aeonium percarneum|thumb|none |- |''Aeonium rubrolineatum'' Svent. |Canary Islands (La Gomera) | |- |''Aeonium saundersii'' Bolle |Canary Islands (La Gomera) |alt=Aeonium saundersii|thumb|none |- |''Aeonium sedifolium'' (Webb ex Bolle) Pit. & Proust. |Canary Islands (Tenerife, La Gomera, La Palma)) |alt=Aeonium sedifolium|thumb|none |- |''Aeonium simsii'' (Sweet) Stearn. |Canary Islands (Gran Canaria) |alt=Aeonium simsii|thumb|none |- |''Aeonium smithii'' (Sims) Webb & Berthel. |Canary Islands (Tenerife) |alt=Aeonium smithii|thumb|none |- |''Aeonium spathulatum'' (Hornem.) Praeger |Canary Islands (Gran Canaria, Tenerife; La Gomera, La Palma, El Hierro) |alt=Aeonium spathulatum|thumb|none |- |''Aeonium stuessyi'' H.-Y. Liu |Ethiopia, Kenya, Tanzania | |- |''Aeonium tabuliforme'' (Haw.) Webb & Berthel. |Canary Islands (Tenerife) |alt=Aeonium tabuliforme|thumb|none |- |''Aeonium undulatum'' Webb & Berthel. |Canary Islands (Gran Canaria) |alt=Aeonium undulatum|thumb|none |- |''Aeonium urbicum'' (C. Sm. ex Hornem.) Webb & Berthel. |Canary Islands (Tenerife) |alt=Aeonium urbicum|thumb|none |- |''Aeonium valverdense'' (Praeger) Praeger |Canary Islands (El Hierro) |alt=Aeonium valverdense|thumb|none |}
== Hybrids == Much hybridising has been done, resulting in several cultivars of mixed or unknown parentage. The following species and cultivars have gained the Royal Horticultural Society's Award of Garden Merit:- {{div col | colwidth = 20em}} *''Aeonium tabuliforme''<ref>{{cite web | url = https://www.rhs.org.uk/Plants/509/Aeonium-tabuliforme/Details | title = ''Aeonium tabuliforme'' | publisher = RHS | access-date = 27 February 2020}}</ref> *''Aeonium haworthii''<ref>{{cite web | url = https://www.rhs.org.uk/Plants/504/Aeonium-haworthii/Details | title = ''Aeonium haworthii'' | publisher = RHS | access-date = 27 February 2020}}</ref> *''Aeonium haworthii'' 'Variegatum'<ref>{{cite web | url = https://www.rhs.org.uk/Plants/83865/Aeonium-haworthii-Variegatum-(v)/Details | title = ''Aeonium haworthii'' 'Variegatum' | publisher = RHS | access-date = 27 February 2020}}</ref> *''Aeonium'' 'Blushing Beauty'<ref>{{cite web | url = https://www.rhs.org.uk/Plants/227610/Aeonium-Blushing-Beauty/Details | title = ''Aeonium'' 'Blushing Beauty' | publisher = RHS | access-date = 27 February 2020}}</ref> *''Aeonium'' 'Sunburst'<ref>{{cite web | url = https://www.rhs.org.uk/Plants/314094/Aeonium-Sunburst-(v)/Details | title = ''Aeonium'' 'Sunburst' | publisher = RHS | access-date = 27 February 2020}}</ref> *''Aeonium'' 'Zwartkop'<ref>{{cite web | url = https://www.rhs.org.uk/Plants/26342/Aeonium-Zwartkop/Details | title = ''Aeonium'' 'Zwartkop' | publisher = RHS | access-date = 27 February 2020}}</ref> {{div col end}}Hybridising between Aeonium species or cultivars and other Crassulaeceae species or cultivars has produced intergeneric crosses:
* x ''Semponium '''Sienna' (''Sempervivum'' 'Green Ice' x ''Aeonium'' 'Ice Warrior').<ref>{{Cite web |title=Graham Rice's new plants blog: Super succulent is Chelsea Plant of the Year star / RHS Gardening |url=https://www.rhs.org.uk/plants/plants-blogs/plants/september-2021/semponium-sienna |access-date=2022-06-20 |website=www.rhs.org.uk |language=en-gb}}</ref> * ''x Semponium'' 'Destiny' - winner of the Royal Horticultural Society Chelsea Flower Show 'Chelsea Plant of the Year 2022' award.<ref>{{Cite web |title=The RHS Chelsea Flower Show Plant of the Year / RHS Gardening |url=http://www.rhs.org.uk/shows-events/rhs-chelsea-flower-show/news/2022/plant-of-the-year |access-date=2022-06-20 |website=www.rhs.org.uk |language=en-gb}}</ref>
Some species have been introduced in California.<ref>{{Cite web | url = http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=100676 | title = Aeonium in Flora of North America @ efloras.org | website = www.efloras.org | access-date = 2016-10-15 }}</ref>
UK national collections of aeoniums are held by Mellie Lewis at Clun in Shropshire<ref>{{Cite web|url=https://www.plantheritage.org.uk/how-can-you-help/sponsor-the-national-plant-collections/sponsor-the-national-plant-collections-follow-aeonium/|title=Join Plant Heritage | Conserving the diversity of garden plants|website=www.plantheritage.org.uk}}</ref> and by Inverewe at Poolewe, Wester Ross in Scotland.<ref>{{Cite web|url=https://www.nts.org.uk/stories/a-glimpse-into-plant-evolution-through-aeoniums|title=A glimpse into plant evolution through…|first=National Trust for|last=Scotland|date=April 22, 2022|website=National Trust for Scotland}}</ref>
==Images== <gallery> File:Aeonium-arboreum-'Atropurpu.jpg|''Aeonium arboreum'' 'Atropurpureum' File:Aeonium aureum (≡ Greenovia. aurea) (Marianne Perdomo) 1.jpg|''Aeonium aureum'' File:Aeonium castello-paivae.jpg|''Aeonium castello-paivae'' File:Aeonium decorum P1050445.JPG|''Aeonium decorum'' File:Aeonium lindleyi P1050450.JPG|''Aeonium lindleyi'' File:Aeonium nobile.jpg|''Aeonium nobile'' File:Aeonium simsii P1050451.JPG|''Aeonium simsii'' File:Aeonium smithii 10-5-2008 12-49-17.JPG|''Aeonium smithii'' File:Aeonium tabuliforme PICT033.jpg|''Aeonium tabuliforme'' File:Aeonium tabuliforme (7577650498).jpg|''Aeonium tabuliforme'' bearing inflorescence File:Aeonium tabuliforme PICT2232.jpg|Detail of ''Aeonium tabuliforme'' flower File:Aeonium tabuliforme x arboreum 'Zwartkop' 2.jpg|''Aeonium tabuliforme'' × ''arboreum'' 'Zwartkop' File:Aeonium undulatum 092.JPG|''Aeonium undulatum'' File:Aeonium valverdense PICT0545.jpg|''Aeonium valverdense'' </gallery>
==References== {{Commons}} {{Wikispecies}} {{Reflist}} * R. Nyffeler, "Aeonium", in Urs Eggli, ed. ''Illustrated Handbook of Succulent Plants: Crassulaceae'' (Springer, 2003) {{ISBN|3-540-41965-9}} * M. Cristini, "The Genus Aeonium" (Rome, 2022) {{ISBN|978-88-901345-6-2}}
{{Taxonbar|from=Q152874}} {{Authority control}}
Category:Aeonium Category:Crassulaceae genera