Canarina is a small genus of flowering plants in the bellflower family, Campanulaceae, within the order Asterales. It comprises herbaceous perennial vines bearing large, pendant, bell-shaped flowers. The genus was described by Linnaeus in his Mantissa Plantarum (1771).
The genus has a striking disjunct distribution, with one species, Canarina canariensis (the Canary Island bellflower), endemic to the laurel forests of the Canary Islands, and the other two species — Canarina abyssinica and Canarina eminii — native to Ethiopia and the tropical highlands of East Africa, respectively.
Canarina canariensis, the best-known and most widely cultivated member of the genus, is grown as an ornamental for its large orange, bell-shaped flowers, and has received the Royal Horticultural Society's Award of Garden Merit. In frost-prone climates it is typically grown under glass over winter.
Canarina canariensis is notable in pollination biology as part of a group of unrelated Canarian plants — including species of Isoplexis and Lotus — that show adaptations for bird pollination (ornithophily). It was once hypothesized that these flowers had originally been pollinated by sunbirds that subsequently went extinct on the Canary Islands, which was used to explain why some of these plants are rare and considered endangered. More recent research has instead shown that the flowers are adequately pollinated by generalist, non-specialist birds, particularly the Canary Islands chiffchaff and the Canary Island spectacled warbler. Consistent with pollination by these less-specialized, infrequent visitors, the flowers show specific adaptations such as unusually long flower lifespans and nectar with a hexose-dominated sugar composition.
Distribution
Canarina has a disjunct range: Canarina canariensis is endemic to the laurel forests of the Canary Islands, while Canarina abyssinica (Ethiopia) and Canarina eminii (tropical East Africa) occur in the highlands of East and Central Africa. GBIF distribution records additionally list Kenya, Tanzania, Uganda, Burundi, Rwanda, DR Congo, Malawi, and Sudan/South Sudan for the African species.
Ecology
Canarina canariensis is part of a group of unrelated Canarian plants adapted for bird pollination. Once thought to depend on sunbirds that had gone extinct on the islands, the flowers are now known to be pollinated by generalist birds — chiefly the Canary Islands chiffchaff and the Canary Island spectacled warbler — and show adaptations such as extended flower lifespans and hexose-dominated nectar to suit these less-specialized, infrequent visitors.
Cultivation
Canarina canariensis is grown as an ornamental for its bell-shaped flowers and has received the Royal Horticultural Society's Award of Garden Merit. In frost-prone areas it is best grown under glass over winter.
Conservation
Some Canarian bird-pollinated species related to Canarina canariensis are rare and considered endangered, a pattern noted in the pollination-biology literature (Vogel 1954; Vogel et al. 1984; Olesen 1985; Valido et al. 2004).
Taxonomy Notes
Canarina L. (Campanulaceae, Asterales) was published in Linnaeus's Mantissa Plantarum 2: 588 (1771). The genus contains three species with a disjunct Canary Islands / East Africa distribution: C. canariensis (Canary Islands), C. abyssinica (Ethiopia), and C. eminii (East Africa). Recorded synonyms include Mindium and Pernetya.
