Aeonium
{{Short description|Genus of succulents}}
{{Automatic taxobox
| image = Aeonium undulatum.JPG
| image_caption = Saucer-plant (Aeonium undulatum)
| display_parents = 2
| taxon = Aeonium
| 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).{{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
}} 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. 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,{{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}}{{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}} 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:{{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}}
| class="wikitable sortable"
|+ !Species !Distribution !class=unsortable| |
| Aeonium aizoon (Bolle) T.H.M.Mes
|Canary Islands (Tenerife) |
| Aeonium appendiculatum Bañares
|Canary Islands (La Gomera) |
| Aeonium arboreum (L.) Webb & Berthel.
|Canary Islands (Gran Canaria, Tenerife, La Gomera, La Palma, El Hierro); Morocco |
| Aeonium aureum (C.Sm. ex Hornem.) T.H.M.Mes
|Canary Islands (Gran Canaria, Tenerife) |
| Aeonium balsamiferum Webb & Berthel.
|Canary Islands (Lanzarote, Fuerteventura) |
| Aeonium canariense (L.) Webb & Berthel.
|Canary Islands (Gran Canaria, Tenerife; La Gomera, La Palma, El Hierro) |
| Aeonium castello-paivae Bolle
|Canary Islands (La Gomera) |
| Aeonium ciliatum (Willd.) Webb & Berthel.
|Canary Islands (Tenerife) |
| Aeonium cuneatum Webb & Berthel.
|Canary Islands (Tenerife) |
| Aeonium davidbramwelii H.Y.Liu
|Canary Islands (La Palma) |
| Aeonium decorum Webb ex Bolle
|Canary Islands (Tenerife, La Gomera) |
| Aeonium dodrantale (Willd.) T.H.M.Mes
|Canary Islands (Tenerife) |File:Aeonium dodrantale in Botanischer Garten Muenster (1).jpg |
| Aeonium glandulosum (Aiton) Webb & Berthel.
|Maderia (Madeira, Desertas, Porto Santo) |
| Aeonium glutinosum (Aiton) Webb & Berthel.
|Madeira (Madeira, Desertas) |
| Aeonium gomerense (Praeger) Praeger
|Canary Islands (La Gomera) |
| Aeonium goochiae (Christ.) Praeger
|Canary Islands (La Palma) |
| Aeonium gorgoneum J. A. Schmidt
|Cabo Verde (Santo Antão, São Nicolau, São Vicente) |
| Aeonium haworthii (Salm-Dyck ex Webb & Berthel.) Webb & Berthel.
|Canary Islands (Tenerife) |
| Aeonium hierrense (R. P. Murray) Pit. & Proust.
|Canary Islands (La Palma, El Hierro) |
| Aeonium lancerottense (Praeger) Praeger
|Canary Islands (Lanzarote) |
| Aeonium leucoblepharum Webb ex A. Richard
|Yemen, Ethiopia, Sudan, Kenya, Uganda |
| Aeonium lindleyi Webb & Berthel.
|Canary Islands (Tenerife) |
| Aeonium liui Arango
|Canary Islands (Tenerife) | |
| Aeonium nobile (Praeger) Praeger
|Canary Islands (La Palma) |File:Aeonium nobile - Botanischer Garten, Frankfurt am Main - DSC02375.JPG |
| Aeonium percarneum (R. P. Murray) Pit. & Proust.
|Canary Islands (Gran Canaria) |
| Aeonium rubrolineatum Svent.
|Canary Islands (La Gomera) | |
| Aeonium saundersii Bolle
|Canary Islands (La Gomera) |
| Aeonium sedifolium (Webb ex Bolle) Pit. & Proust.
|Canary Islands (Tenerife, La Gomera, La Palma)) |
| Aeonium simsii (Sweet) Stearn.
|Canary Islands (Gran Canaria) |
| Aeonium smithii (Sims) Webb & Berthel.
|Canary Islands (Tenerife) |
| Aeonium spathulatum (Hornem.) Praeger
|Canary Islands (Gran Canaria, Tenerife; La Gomera, La Palma, El Hierro) |
| Aeonium stuessyi H.-Y. Liu
|Ethiopia, Kenya, Tanzania | |
| Aeonium tabuliforme (Haw.) Webb & Berthel.
|Canary Islands (Tenerife) |
| Aeonium undulatum Webb & Berthel.
|Canary Islands (Gran Canaria) |
| Aeonium urbicum (C. Sm. ex Hornem.) Webb & Berthel.
|Canary Islands (Tenerife) |
| Aeonium valverdense (Praeger) Praeger
|Canary Islands (El Hierro) |File:Aeonium valverdense in Tropengewächshäuser des Botanischen Gartens 01.jpg |
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{{cite web | url = https://www.rhs.org.uk/Plants/509/Aeonium-tabuliforme/Details | title = Aeonium tabuliforme | publisher = RHS | access-date = 27 February 2020}}
- Aeonium haworthii{{cite web | url = https://www.rhs.org.uk/Plants/504/Aeonium-haworthii/Details
| title = Aeonium haworthii | publisher = RHS | access-date = 27 February 2020}}
- Aeonium haworthii 'Variegatum'{{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}}
- Aeonium 'Blushing Beauty'{{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}}
- Aeonium 'Sunburst'{{cite web | url = https://www.rhs.org.uk/Plants/314094/Aeonium-Sunburst-(v)/Details
| title = Aeonium 'Sunburst' | publisher = RHS | access-date = 27 February 2020}}
| title = Aeonium 'Zwartkop' | publisher = RHS | access-date = 27 February 2020}}
{{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').{{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}}
- x Semponium 'Destiny' - winner of the Royal Horticultural Society Chelsea Flower Show 'Chelsea Plant of the Year 2022' award.{{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}}
Some species have been introduced in California.{{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
}}
UK national collections of aeoniums are held by Mellie Lewis at Clun in Shropshire{{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}} and by Inverewe at Poolewe, Wester Ross in Scotland.{{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}}
Images
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
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}}