Aeonium


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. While most of them are native to the Canary Islands, some are found in Madeira, Cape Verde, Morocco, in East Africa 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.
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, the genus Greenovia has been placed within Aeonium''.

Species and distribution

All but two species are native to at least one of three different Macaronesian archipelagos Most aeoniums are from the Canary Islands, The only species not native to these three Macaronesian island groups 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:
SpeciesDistribution
Aeonium aizoon T.H.M.MesCanary Islands
Aeonium appendiculatum BañaresCanary Islands
Aeonium arboreum Webb & Berthel.Canary Islands ;
Morocco
Aeonium aureum T.H.M.MesCanary Islands
Aeonium balsamiferum Webb & Berthel.Canary Islands
Aeonium canariense Webb & Berthel.Canary Islands
Aeonium castello-paivae BolleCanary Islands
Aeonium ciliatum Webb & Berthel.Canary Islands
Aeonium cuneatum Webb & Berthel.Canary Islands
Aeonium davidbramwelii H.Y.LiuCanary Islands
Aeonium decorum Webb ex BolleCanary Islands
Aeonium dodrantale T.H.M.MesCanary Islands
Aeonium glandulosum Webb & Berthel.Maderia
Aeonium glutinosum Webb & Berthel.Madeira
Aeonium gomerense PraegerCanary Islands
Aeonium goochiae PraegerCanary Islands
Aeonium gorgoneum J. A. SchmidtCabo Verde
Aeonium haworthii Webb & Berthel.Canary Islands
Aeonium hierrense Pit. & Proust.Canary Islands
Aeonium lancerottense PraegerCanary Islands
Aeonium leucoblepharum Webb ex A. RichardYemen, Ethiopia, Sudan, Kenya, Uganda
Aeonium lindleyi Webb & Berthel.Canary Islands
Aeonium liui ArangoCanary Islands
Aeonium nobile PraegerCanary Islands
Aeonium percarneum Pit. & Proust.Canary Islands
Aeonium rubrolineatum Svent.Canary Islands
Aeonium saundersii BolleCanary Islands
Aeonium sedifolium Pit. & Proust.Canary Islands )
Aeonium simsii Stearn.Canary Islands
Aeonium smithii Webb & Berthel.Canary Islands
Aeonium spathulatum PraegerCanary Islands
Aeonium stuessyi H.-Y. LiuEthiopia, Kenya, Tanzania
Aeonium tabuliforme Webb & Berthel.Canary Islands
Aeonium undulatum Webb & Berthel.Canary Islands
Aeonium urbicum Webb & Berthel.Canary Islands
Aeonium valverdense PraegerCanary Islands

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:-
  • 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:
Some species have been introduced in California.
UK national collections of aeoniums are held by Mellie Lewis at Clun in Shropshire and by Inverewe at Poolewe, Wester Ross in Scotland.

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