Aeonium Explained

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).[1] 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, 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 (the Canary Islands, Madeira, or Cape Verde) Most aeoniums are from the Canary Islands,[2] [3] 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:[4]

Aeonium aizoon (Bolle) T.H.M.MesCanary Islands (Tenerife)
Aeonium appendiculatum BañaresCanary 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.MesCanary 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 BolleCanary Islands (La Gomera)
Aeonium ciliatum (Willd.) Webb & Berthel.Canary Islands (Tenerife)
Aeonium cuneatum Webb & Berthel.Canary Islands (Tenerife)
Aeonium davidbramwelii H.Y.LiuCanary Islands (La Palma)
Aeonium decorum Webb ex BolleCanary Islands (Tenerife, La Gomera)
Aeonium dodrantale (Willd.) T.H.M.MesCanary Islands (Tenerife)
Aeonium glandulosum (Aiton) Webb & Berthel.Maderia (Madeira, Desertas, Porto Santo)
Aeonium glutinosum (Aiton) Webb & Berthel.Madeira (Madeira, Desertas)
Aeonium gomerense (Praeger) PraegerCanary Islands (La Gomera)
Aeonium goochiae (Christ.) PraegerCanary Islands (La Palma)
Aeonium gorgoneum J. A. SchmidtCabo 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) PraegerCanary Islands (Lanzarote)
Aeonium leucoblepharum Webb ex A. RichardYemen, Ethiopia, Sudan, Kenya, Uganda
Aeonium lindleyi Webb & Berthel.Canary Islands (Tenerife)
Aeonium liui ArangoCanary Islands (Tenerife)
Aeonium nobile (Praeger) PraegerCanary Islands (La Palma)
Aeonium percarneum (R. P. Murray) Pit. & Proust.Canary Islands (Gran Canaria)
Aeonium rubrolineatum Svent.Canary Islands (La Gomera)
Aeonium saundersii BolleCanary 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.) PraegerCanary Islands (Gran Canaria, Tenerife; La Gomera, La Palma, El Hierro)
Aeonium stuessyi H.-Y. LiuEthiopia, 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) PraegerCanary Islands (El Hierro)

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:-

Hybridising between Aeonium species or cultivars and other Crassulaeceae species or cultivars has produced intergeneric crosses:

Some species have been introduced in California.[13]

UK national collections of aeoniums are held by Mellie Lewis at Clun in Shropshire[14] and by Inverewe at Poolewe, Wester Ross in Scotland.[15]

References

Notes and References

  1. Book: Eggli. U.. Newton. L.E.. Etymological Dictionary of Succulent Plant Names. Springer Berlin Heidelberg. 2004. 978-3-540-00489-9. 25 September 2018. 3.
  2. Book: Bramwell . D. . Wild flowers of the Canary Islands . Bramwell . Z. . Editorial Rueda . 2001 . 84-7207-129-4 . Madrid, Spain.
  3. Web site: International Crassulaceae Network: Aeonium . 19 February 2017 . International Crassulaceae Network.
  4. Web site: Aeonium Webb & Berthel. . 2023 . Plants of the World Online . Royal Botanic Gardens, Kew. 13 April 2023.
  5. Web site: Aeonium tabuliforme . RHS . 27 February 2020.
  6. Web site: Aeonium haworthii . RHS . 27 February 2020.
  7. Web site: Aeonium haworthii 'Variegatum' . RHS . 27 February 2020.
  8. Web site: Aeonium 'Blushing Beauty' . RHS . 27 February 2020.
  9. Web site: Aeonium 'Sunburst' . RHS . 27 February 2020.
  10. Web site: Aeonium 'Zwartkop' . RHS . 27 February 2020.
  11. Web site: Graham Rice's new plants blog: Super succulent is Chelsea Plant of the Year star / RHS Gardening . 2022-06-20 . www.rhs.org.uk . en-gb.
  12. Web site: The RHS Chelsea Flower Show Plant of the Year / RHS Gardening . 2022-06-20 . www.rhs.org.uk . en-gb.
  13. Web site: Aeonium in Flora of North America @ efloras.org. www.efloras.org. 2016-10-15.
  14. Web site: Join Plant Heritage | Conserving the diversity of garden plants. www.plantheritage.org.uk.
  15. Web site: A glimpse into plant evolution through…. National Trust for. Scotland. April 22, 2022. National Trust for Scotland.