''Aeonium'', the tree houseleeks, is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

of about 35 species of succulent, subtropical plants of the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Crassulaceae The Crassulaceae (from Latin ''crassus'', thick), also known as the stonecrop family or the orpine family, are a diverse family of dicotyledon flowering plants characterized by succulent leaves and a unique form of photosynthesis, known as Cr ...

. Many species are popular in horticulture. The genus name comes from the ancient Greek αἰώνιος / aiōnios (ageless). While most of them are

native Native may refer to: People * Jus soli, citizenship by right of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Native Americans (disambiguation) In arts and enterta ...

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 Mo ...

, some are found in

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 ...

Cape Verde , national_anthem = () , official_languages = Portuguese , national_languages = Cape Verdean Creole , capital = Praia , coordinates = , largest_city = capital , demonym ...

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 ...

, in East Africa (

Ethiopia Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the Er ...

Somalia Somalia, , Osmanya script: 𐒈𐒝𐒑𐒛𐒐𐒘𐒕𐒖; ar, الصومال, aṣ-Ṣūmāl officially the Federal Republic of SomaliaThe ''Federal Republic of Somalia'' is the country's name per Article 1 of thProvisional Constitut ...

Uganda }), is a landlocked country in East Africa. The country is bordered to the east by Kenya, to the north by South Sudan, to the west by the Democratic Republic of the Congo, to the south-west by Rwanda, and to the south by Tanzania. The south ...

Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands ...

and

Kenya ) , national_anthem = " Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...

) and

Yemen Yemen (; ar, ٱلْيَمَن, al-Yaman), officially the Republic of Yemen,, ) is a country in Western Asia. It is situated on the southern end of the Arabian Peninsula, and borders Saudi Arabia to the north and Oman to the northeast an ...

Description

The succulent leaves are typically arranged on a

basal Basal or basilar is a term meaning ''base'', ''bottom'', or ''minimum''. Science * Basal (anatomy), an anatomical term of location for features associated with the base of an organism or structure * Basal (medicine), a minimal level that is nec ...

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 ''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 ...

'', '' Aichryson'' and '' Monanthes'', as can be seen by their similar

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanism ...

and

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed ...

s. Recently, the genus ''Greenovia'' has been placed within ''Aeonium''.

Species and distribution

All but two species are native to at least one of three different

Macaronesia Macaronesia (Portuguese: ''Macaronésia,'' Spanish: ''Macaronesia'') is a collection of four volcanic archipelagos in the North Atlantic, off the coasts of Africa and Europe. Each archipelago is made up of a number of Atlantic oceanic islands ...

n archipelagos (the

, or

Cape Verde , national_anthem = () , official_languages = Portuguese , national_languages = Cape Verdean Creole , capital = Praia , coordinates = , largest_city = capital , demonym ...

) Most aeoniums are from the

, The only species not native to these three Macaronesian island groups (''Aeonium stuessyi'' and Aeonium ''leucoblepharum'') are found in

Kenya ) , national_anthem = " Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...

and

; and Ethiopia, Kenya, Sudan,

and

, respectively. '' Aeonium arboreum'' is native to both the Canary Islands and Morocco.

Hybrids

Much hybridising has been done, resulting in several

cultivars 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 ...

of mixed or unknown parentage. The following species and cultivars have gained 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 (No ...

’s

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 ...

:- *''Aeonium tabuliforme'' *''Aeonium haworthii'' *''Aeonium haworthii'' 'Variegatum' *''Aeonium'' 'Blushing Beauty' *''Aeonium'' 'Sunburst' *''Aeonium'' 'Zwartkop' 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’). * ''x Semponium'' 'Destiny' - winner of the

Chelsea Flower Show The RHS Chelsea Flower Show, formally known as the ''Great Spring Show'',Phil Clayton, ''The Great Temple Show'' in ''The Garden'' 2008, p.452, The Royal Horticultural Society is a garden show held for five days in May by the Royal Horticultural ...

'Chelsea Plant of the Year 2022' award. Some species have been introduced in

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the ...

. UK national collections of aeoniums are held by Mellie Lewis at

Clun Clun ( cy, Colunwy) is a town in south west Shropshire, England, and the Shropshire Hills AONB, Shropshire Hills Area of Outstanding Natural Beauty. The 2011 United Kingdom census, census recorded 680 people living in the town.Combined populat ...

Shropshire Shropshire (; alternatively Salop; abbreviated in print only as Shrops; demonym Salopian ) is a landlocked historic county in the West Midlands region of England. It is bordered by Wales to the west and the English counties of Cheshire to ...

and by Inverewe at Poolewe,

Wester Ross Wester Ross () is an area of the Northwest Highlands of Scotland in the council area of Highland. The area is loosely defined, and has never been used as a formal administrative region in its own right, but is generally regarded as lying to t ...

in Scotland.

Selected species

* '' Aeonium aizoon'' * ''

Aeonium appendiculatum ''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 (agele ...

'' * '' Aeonium arboreum'' * '' Aeonium aureum'' * '' Aeonium balsamiferum'' * ''

Aeonium canariense ''Aeonium canariense'' is a species of flowering plant in the family Crassulaceae. It is endemic to the island of Tenerife in the Canary Islands The Canary Islands (; es, Canarias, ), also known informally as the Canaries, are a Spanish ...

'' * ''

Aeonium castello-paivae ''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 (agele ...

'' * '' Aeonium ciliatum'' * ''

Aeonium cuneatum ''Aeonium cuneatum'' is a succulent species of flowering plant in the family '' Crassulaceae''. It has a large leaf rosette and no stem. The leaves are smooth but have a grey shine to the upper surface which can be rubbed. It offshoots easily wh ...

'' * ''

Aeonium davidbramwellii ''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 (age ...

'' * ''

Aeonium decorum ''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 (age ...

'' * ''

Aeonium glandulosum ''Aeonium glandulosum'' is a species of subshrub of the family Crassulaceae endemic to the Madeira archipelago (Madeira Island, Porto Santo Island and Desertas Islands). Description It is a biennial or perennial glandular-pubescent sub-shrub w ...

'' * '' Aeonium glutinosum'' * '' Aeonium gomerense'' * '' Aeonium gorgoneum'' * '' Aeonium goochiae'' * '' Aeonium haworthii'' * ''

Aeonium hierrense ''Aeonium hierrense'' is a species of succulent flowering plant in the family '' Crassulaceae'' that is endemic to the island of El Hierro in the Canary islands. It has whorls of strongly ciliate The ciliates are a group of alveolates charact ...

'' * ''

Aeonium leucoblepharum ''Aeonium leucoblepharum'' is a succulent flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('con ...

'' * '' Aeonium lindleyi'' * ''

Aeonium nobile ''Aeonium nobile'' is a succulent, subtropical flowering plant in the family Crassulaceae.

'' * '' Aeonium sedifolium'' * '' Aeonium simsii'' * '' Aeonium smithii'' * '' Aeonium spathulatum'' * '' Aeonium tabuliforme'' * '' Aeonium undulatum'' – saucer plant * ''

Aeonium urbicum ''Aeonium urbicum'' is a succulent species of flowering plant in the family Crassulaceae. It is endemic to Tenerife, one of the Canary Islands The Canary Islands (; es, Canarias, ), also known informally as the Canaries, are a Spanish a ...

'' * '' Aeonium valverdense''

Images

File:Aeonium tabuliforme (7577650498).jpg, '' Aeonium tabuliforme'' bearing

File:Aeonium tabuliforme PICT2232.jpg, Detail of '' Aeonium tabuliforme'' flower 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 labuliforme.jpg, ''Aeonium tabuliforme'' File:Aeonium tabuliforme x arboreum 'Zwartkop' 2.jpg, ''Aeonium tabuliforme × arboreum 'Zwartkop' #2'' File:Aeonium undulatum 092.JPG, ''Aeonium undulatum'' File:Aeonium valverdense PICT0545.jpg, ''Aeonium valverdense''

References

* R. Nyffeler, "Aeonium", in Urs Eggli, ed. ''Illustrated Handbook of Succulent Plants: Crassulaceae'' (Springer, 2003) * M. Cristini, "The Genus Aeonium" (Rome, 2022) {{Taxonbar, from=Q152874 Crassulaceae genera