Kōwhai and kākā beak are native members of the pea family, with large, showy flowers and neat, fern-like compound leaves. They are well-known and widely cultivated. Most of the eight kōwhai species are trees. In spring, their rich yellow flowers are seen in forests and shrublands throughout New Zealand.
The two kākā beak species, with their brilliant red, pink or white flowers (named for their resemblance to the curved beak of the kākā parrot) have always been rare and only found locally distributed in northern shrublands. They are now one of the rarest native plants in the wild.
Sophora microphylla is the most common kōwhai. It grows mostly on forest margins, in open places, and along river banks throughout the two main islands, although its distribution is patchy. This kōwhai has small leaves and a divaricating, twiggy juvenile stage that can persist around the base of the adult trees. The trees can reach 25 metres in height, and they usually have a single trunk and weeping branches.
In 2001 scientists described five new species of kōwhai that had previously been grouped with S. microphylla. They include:
- S. godleyi, which lacks a divaricating juvenile phase and grows on mudstone in the central North island
- S. molloyi, a hardy plant of the exposed headlands in Cook Strait.
S. tetraptera is showier than S. microphylla, with larger, conspicuously keeled flowers and big grey-green leaves. It is the most popular garden tree. It is now widely naturalised, but once grew only in the eastern North Island, from sea level to 450 metres. It reaches 15 metres in height and is often multi-stemmed. This species does not have a divaricating juvenile stage.
The smallest kōwhai species, S. prostrata, retains its shrubby divaricating form and is restricted to the eastern South Island.
Kōwhai ngutu-kākā – kākā beak
Clianthus maximus is a sprawling shrub. It is scattered in regenerating scrubland – often at the tops and bases of unstable cliffs and rock falls – on the East Coast of the North Island south to northern Hawke’s Bay and east to Te Urewera. Inland specimens may have been planted, as they are found near former Māori settlements and gardens. This species has dark green leaves with a shiny upper surface and dark scarlet flowers. It may produce a few flowers throughout the year, but most flowering occurs between early spring and late summer.
C. puniceus is now found in only one site in the wild, and those at this site may be the result of Māori cultivation. This kākā beak may have once grown naturally in Northland and the eastern side of the Hauraki Gulf. It has matt-green leaves and slightly smaller scarlet, pink, or white flowers, often with a white stripe.