Cunonia is a genus of evergreen shrubs and trees in the family Cunoniaceae (order Oxalidales), first described by Linnaeus in 1759. It shows a strikingly disjunct distribution: a single species, Cunonia capensis, grows in southern Africa from the Western Cape eastwards to Mozambique, while the remaining roughly two dozen species are endemic to New Caledonia in the South Pacific — the only two regions on Earth where the genus occurs naturally. The GBIF backbone lists 27 accepted taxa in the genus, including named natural hybrids among the New Caledonian species, such as Cunonia × alticola and Cunonia × koghicola.
Leaves are opposite, simple or pinnate, with margins ranging from entire to serrate. A distinctive feature of the genus is its conspicuous interpetiolar stipules, which press together to enclose the developing bud in a spoon-like shape — the origin of the English common name "butterspoon tree" for Cunonia capensis. Flowers are bisexual and borne in dense, bottlebrush-like racemes; colour varies by species from white or cream to red, pink, purple, or green. The scented flowers attract insects, including honeybees. Fruit is a two-horned capsule that splits first at the base and then vertically, releasing fine, winged seed dispersed by wind and, in Cunonia capensis, also by birds that carry the sticky seed on their feathers and bills.
Cunonia capensis, the genus's best-documented member, is a fast-growing forest tree reaching about 10 m in closed forest (around 5 m when grown in the open), typically found along watercourses and in moist forest habitats. Its wood, known locally as rooiels ("red alder") for its resemblance to true alders, has been used for furniture, and the tree has a history of traditional medicinal use for nervous complaints. The genus name honours Johann Christian Cuno, an 18th-century poet who published a book of verse describing the exotic plants in his own garden.
Etymology
Named by Linnaeus for Johann Christian Cuno, an 18th-century poet who published a book of verse about his own garden, in which many exotic plants grew.
Distribution
Cunonia has a disjunct range: about 24 species endemic to New Caledonia in the Pacific, and one species, Cunonia capensis, native to southern Africa, occurring in forest and along watercourses from the Western Cape eastwards to Mozambique. These two regions are the only places the genus occurs naturally.
Ecology
Flowers are scented and attract insects, including honeybees. Seed is fine and winged; in Cunonia capensis it is also sticky and dispersed both by wind and by birds that carry it on their feathers, legs, and bills. Cunonia capensis is a fast-growing forest tree, reaching up to 10 m in closed forest but only around 5 m when grown in the open, favouring moist habitats along watercourses.
Cultivation
Cunonia capensis, the most widely cultivated member of the genus, prefers a temperate, sheltered, moist site and does not thrive in very hot, dry, or windy conditions, though it tolerates some frost. It is propagated from very fine seed sown in seedling mix and covered lightly, with young plants needing plenty of water and shelter.
Cultural Uses
Cunonia capensis is known by several common names, including butterspoon tree and red alder (English), rooiels (Afrikaans), umqwashube (Xhosa), and umlulama (Zulu). Its fine-grained, relatively hard and heavy wood has been used for furniture, and the tree has reportedly been used to treat nervous complaints.
Taxonomy Notes
Cunonia L. is placed in family Cunoniaceae, order Oxalidales, and was published by Linnaeus in Systema Naturae ed. 10 (1759): 1025. The GBIF backbone lists 27 accepted taxa in the genus, including named natural hybrids among the New Caledonian species (e.g. Cunonia × alticola, Cunonia × koghicola) alongside the roughly 24 non-hybrid New Caledonian species and the single southern African species, C. capensis.
