The genus Aeonium includes at least 35 species of tender, rosetted, leaf succulents mainly from the Canary Islands but also found in Madeira, Morocco and Ethiopia. These succulent plants vary in size from small herbs almost flat against the ground to woody shrubs with stout basal stems supporting one or more disc-shaped rosettes, giving them a distinctive appearance. The generic name comes from the Greek "aionion" = everliving. Flowers are panicles of numerous small yellow or white florets. Some Aeonium species are monocarpic.
Natural hybrids are common and there are many attractive horticultural hybrids and cutivars. The sap of Aeonium lindleyi is a traditional antidote to the toxic sap of Euphorbias e.g. E. canariensis. Aeonium includes the former genera Greenonium and Greenovia (Mountain Roses), which may be seen occasionally on plant labels and in old books. Many species were originally classified as Sempervivums.
Aeonium undulatum, shown here, is a succulent, evergreen subshrub, is one of the larger species of Aeonium with the rosette often over a metre from the ground on a single stem. Other rosettes do not branch off this stem (normally) but grow from the bottom, unlike most aeoniums. The plant is monocarpic so the flowering stem will die when it flowers which is normally after about 5 years. The specific epithet undulatum comes from the Latin unda, meaning "wave" and refers to the wavy leaves. Synonyms include Sempervivum undulatum and Sempervivum youngianum. The common name "saucer plant" is applied to this and other plants of a similar habit. In temperate regions this plant is grown under glass. It has gained the Royal Horticultural Society's Award of Garden Merit.
