Aeonium

Aeonium
	Saucer-plant (Aeonium undulatum)
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Order:	Saxifragales
Family:	Crassulaceae
Subfamily:	Sempervivoideae
Tribe:	Aeonieae
Genus:	Aeonium; Webb & Berthel.
Species
	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).^[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,^[when?] the genus Greenovia has been placed within Aeonium.^{[citation needed]}

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]


Species	Distribution
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)
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)
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)

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^[5]
Aeonium haworthii^[6]
Aeonium haworthii 'Variegatum'^[7]
Aeonium 'Blushing Beauty'^[8]
Aeonium 'Sunburst'^[9]
Aeonium 'Zwartkop'^[10]

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').^[11]
x Semponium 'Destiny' - winner of the Royal Horticultural Society Chelsea Flower Show 'Chelsea Plant of the Year 2022' award.^[12]

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]

Images

Aeonium arboreum 'Atropurpureum'
Aeonium aureum
Aeonium castello-paivae
Aeonium decorum
Aeonium lindleyi
Aeonium nobile
Aeonium simsii
Aeonium smithii
Aeonium tabuliforme
Aeonium tabuliforme bearing inflorescence
Detail of Aeonium tabuliforme flower
Aeonium tabuliforme × arboreum 'Zwartkop'
Aeonium undulatum
Aeonium valverdense

References

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

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

[Eggli_Newton_2004-1] Eggli, U.; Newton, L.E. (2004). Etymological Dictionary of Succulent Plant Names. Springer Berlin Heidelberg. p. 3. ISBN 978-3-540-00489-9. Retrieved 25 September 2018.

[Bramwell2-2] Bramwell, D.; Bramwell, Z. (2001). Wild flowers of the Canary Islands. Madrid, Spain: Editorial Rueda. ISBN 84-7207-129-4.

[ICN2-3] "International Crassulaceae Network: Aeonium". International Crassulaceae Network. Retrieved 19 February 2017.

[POWO-4] "Aeonium Webb & Berthel". Plants of the World Online. Royal Botanic Gardens, Kew. 2023. Retrieved 13 April 2023.

[5] "Aeonium tabuliforme". RHS. Retrieved 27 February 2020.

[6] "Aeonium haworthii". RHS. Retrieved 27 February 2020.

[7] "Aeonium haworthii 'Variegatum'". RHS. Retrieved 27 February 2020.

[8] "Aeonium 'Blushing Beauty'". RHS. Retrieved 27 February 2020.

[9] "Aeonium 'Sunburst'". RHS. Retrieved 27 February 2020.

[10] "Aeonium 'Zwartkop'". RHS. Retrieved 27 February 2020.

[11] "Graham Rice's new plants blog: Super succulent is Chelsea Plant of the Year star / RHS Gardening". www.rhs.org.uk. Retrieved 2022-06-20.

[12] "The RHS Chelsea Flower Show Plant of the Year / RHS Gardening". www.rhs.org.uk. Retrieved 2022-06-20.

[13] "Aeonium in Flora of North America @ efloras.org". www.efloras.org. Retrieved 2016-10-15.

[14] "Join Plant Heritage | Conserving the diversity of garden plants". www.plantheritage.org.uk.

[15] Scotland, National Trust for (April 22, 2022). "A glimpse into plant evolution through…". National Trust for Scotland.

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