Clianthus is a small genus of flowering shrubs in the legume family Fabaceae (order Fabales), endemic to the North Island of New Zealand. Commonly known as kaka beak or kōwhai ngutukākā in Māori, the genus comprises two species recognised today: the critically endangered Clianthus puniceus and the endangered Clianthus maximus.
The plants typically grow to around two metres high, with spreading branches bearing leaf stalks up to 15 cm long carrying several pairs of small leaflets. Their most distinctive feature is their dramatic clusters of flowers that closely resemble the curved beak of the kākā, a native New Zealand parrot — earning the genus its various common names including parrot's beak, parrot's bill, and lobster claw. Flowers are typically vivid red, though cultivars with white to creamy ("Albus") and rosy pink ("Roseus") flowers are also grown.
Taxonomically, Clianthus forms a clade with the New Zealand genus Carmichaelia (New Zealand broom), and together they are part of a broader clade that also includes the Australian genus Swainsona and the New Zealand Montigena (scree pea). Sturt's desert pea (Swainsona formosa), the floral emblem of South Australia, was formerly classified within Clianthus as Clianthus dampieri before being moved to Swainsona.
Both species are now critically threatened in the wild. C. puniceus is known in the wild only from Moturemu Island in the Kaipara Harbour, while C. maximus had declined to just 153 wild plants by 2005, down from over 1000 in 1996. Despite this, both species are cultivated in gardens and C. puniceus has produced multiple award-winning cultivars.
Etymology
The genus name and its common name kaka beak refer to the distinctive shape of the flowers, which closely resemble the curved beak of the kākā (Nestor meridionalis), a native New Zealand parrot. In Māori the plant is called kōwhai ngutukākā. Other English names — parrot's beak, parrot's bill, and lobster claw — all allude to the same floral form.
Distribution
Clianthus is endemic to the North Island of New Zealand. Clianthus puniceus is now known in the wild only on Moturemu Island in the Kaipara Harbour, making it critically endangered. Clianthus maximus occurs mainly in the East Cape region, though its wild population had declined to around 153 plants by 2005.
Conservation
Both species of Clianthus are threatened in the wild. Clianthus puniceus is critically endangered and survives in the wild only on Moturemu Island in the Kaipara Harbour. Clianthus maximus is classified as endangered; a 2005 survey found only 153 wild plants, a sharp decline from over 1000 in 1996. Cultivated lines of C. maximus are descended from very few individuals and lack genetic diversity. C. puniceus is actively cultivated and has produced award-winning garden cultivars, supporting its persistence outside the wild.
History
Specimens of Clianthus were first collected by Joseph Banks and Daniel Solander during Captain Cook's first voyage in 1769. Clianthus puniceus was formally described in 1835. William Colenso identified two species as early as 1847 and described C. maximus in 1885, though Thomas Kirk reduced it to a variety of C. puniceus in 1899; Peter Heenan reinstated it as a separate species in 2000. The plant was traditionally cultivated by the Ngāi Tai ki Tāmaki people on Motukaraka Island, where it was used for nitrogen fixation in kūmara (sweet potato) plantations, and its flowers were fashioned into elaborate garlands for high-ranking women. Kaka beak featured on New Zealand's definitive postage stamps from 1960 to 1969.
Cultivation
Clianthus maximus is widely grown as a garden plant in New Zealand, though cultivated lines are descended from only a few wild plants and have limited genetic diversity. Clianthus puniceus is also cultivated and has given rise to several award-winning cultivars, including forms with white ("Albus") and pink ("Roseus") flowers. Both species flower from spring through to early summer and can flower twice a year or even year-round under suitable conditions.
