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

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of about 35 species of

succulent In botany, succulent plants, also known as succulents, are plants with parts that are thickened, fleshy, and engorged, usually to retain water in arid climates or soil conditions. The word ''succulent'' comes from the Latin word ''sucus'', meani ...

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...

plants of the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Crassulaceae The Crassulaceae (, from Latin ''crassus'', thick), also known as the crassulas, the stonecrops or the orpine family, are a diverse Family (biology), family of dicotyledon angiosperms primarily characterized by succulent leaves and a form of phot ...

. 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 sanguinis'', nationality by blood * '' Jus soli'', nationality by location of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Nat ...

to the

Canary Islands The Canary Islands (; ) or Canaries are an archipelago in the Atlantic Ocean and the southernmost Autonomous communities of Spain, Autonomous Community of Spain. They are located in the northwest of Africa, with the closest point to the cont ...

, some are found in

Madeira Madeira ( ; ), officially the Autonomous Region of Madeira (), is an autonomous Regions of Portugal, autonomous region of Portugal. It is an archipelago situated in the North Atlantic Ocean, in the region of Macaronesia, just under north of ...

Cape Verde Cape Verde or Cabo Verde, officially the Republic of Cabo Verde, is an island country and archipelagic state of West Africa in the central Atlantic Ocean, consisting of ten volcanic islands with a combined land area of about . These islands ...

Morocco Morocco, officially the Kingdom of Morocco, is a country in the Maghreb region of North Africa. It has coastlines on the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to Algeria–Morocc ...

, in East Africa (

Ethiopia Ethiopia, officially the Federal Democratic Republic of Ethiopia, is a landlocked country located in the Horn of Africa region of East Africa. It shares borders with Eritrea to the north, Djibouti to the northeast, Somalia to the east, Ken ...

Somalia Somalia, officially the Federal Republic of Somalia, is the easternmost country in continental Africa. The country is located in the Horn of Africa and is bordered by Ethiopia to the west, Djibouti to the northwest, Kenya to the southwest, th ...

Uganda Uganda, officially the Republic of Uganda, is a landlocked country in East Africa. It 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 ...

Tanzania Tanzania, officially the United Republic of Tanzania, is a country in East Africa within the African Great Lakes region. It is bordered by Uganda to the northwest; Kenya to the northeast; the Indian Ocean to the east; Mozambique and Malawi to t ...

and

Kenya Kenya, officially the Republic of Kenya, is a country located in East Africa. With an estimated population of more than 52.4 million as of mid-2024, Kenya is the 27th-most-populous country in the world and the 7th most populous in Africa. ...

) and

Yemen Yemen, officially the Republic of Yemen, is a country in West Asia. Located in South Arabia, southern Arabia, it borders Saudi Arabia to Saudi Arabia–Yemen border, the north, Oman to Oman–Yemen border, the northeast, the south-eastern part ...

Description

The succulent

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

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 ''Sempervivum'' () is a genus of about 40 species of flowering plants in the family (biology), family Crassulaceae, commonly known as houseleeks. Other common names include liveforever (the source of the taxonomical designation ''Sempervivum'', l ...

'', ''

Aichryson ''Aichryson'' is a genus of 16 species of succulent, subtropical plants, native to the Canary Islands, Azores, and Madeira. The species of ''Aichryson'' are not frost-resistant. They are related to ''Sempervivum, Jovibarba, Greenovia, Aeonium' ...

'' and ''

Monanthes ''Monanthes'' is a genus of small, succulent, subtropical plants of the family Crassulaceae. Most species in the genus are endemic to the Canary Islands, with one species also endemic to the Savage Islands and another to the High Atlas mountains ...

'', as can be seen by their similar

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

and

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

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 (; ) is a collection of four volcanic archipelagos in the Atlantic Ocean#North Atlantic, North Atlantic Ocean, off the coast of North Africa and Europe. Each archipelago is made up of a number of list of islands in the Atlantic Oc ...

n archipelagos (the

, or

) Most aeoniums are from the

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

and

; and Ethiopia, Kenya,

Sudan Sudan, officially the Republic of the Sudan, is a country in Northeast Africa. It borders the Central African Republic to the southwest, Chad to the west, Libya to the northwest, Egypt to the north, the Red Sea to the east, Eritrea and Ethiopi ...

and

, respectively. ''

Aeonium arboreum ''Aeonium arboreum'', the tree aeonium, tree houseleek, or Irish rose, is a succulent, Subtropics, subtropical subshrub in the flowering plant family Crassulaceae. Description ''Aeonium arboreum'' grows as a less branched subshrub and reaches s ...

'' is native to both the Canary Islands and Morocco. Species accepted by

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

as of April 2023:

Hybrids

Much hybridising has been done, resulting in several

cultivars A cultivar is a kind of cultivated plant that people have selected for desired traits and which retains those traits when propagated. Methods used to propagate cultivars include division, root and stem cuttings, offsets, grafting, tissue cult ...

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 ...

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

:- *''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 So ...

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

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

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

Clun Clun 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 populations for the t ...

Shropshire Shropshire (; abbreviated SalopAlso used officially as the name of the county from 1974–1980. The demonym for inhabitants of the county "Salopian" derives from this name.) is a Ceremonial counties of England, ceremonial county in the West M ...

and by Inverewe at

Poolewe Poolewe () is a small village in Wester Ross in the North West Highlands of Scotland, about northwest of Inverness, by Loch Ewe. The River Ewe, one of the shortest in Scotland, joins the sea less than from Inverewe Garden, renowned for its sub ...

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 th ...

in 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

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

* R. Nyffeler, "Aeonium", in

Urs Eggli Urs (from ''‘Urs'') or Urus (literal meaning wedding), is the death anniversary of a Sufi saint, usually held at the saint's dargah (shrine or tomb). In most Sufi orders such as Naqshbandiyyah, Suhrawardiyya, Chishtiyya, Qadiriyya, etc. the ...

, ed. ''Illustrated Handbook of Succulent Plants: Crassulaceae'' (Springer, 2003) * M. Cristini, "The Genus Aeonium" (Rome, 2022) {{Authority control Crassulaceae genera