Corokia is a small genus of shrubs and small trees in the family Argophyllaceae, placed within the order Asterales. The genus was first described in 1839 and comprises around six species native primarily to New Zealand, with outlying species in New South Wales (Australia), Lord Howe Island, the Chatham Islands, and the remote Polynesian island of Rapa Iti.
The genus is most recognizable by its strongly divaricating, zigzagging branch architecture — so pronounced in Corokia cotoneaster that the species earned the common name wire-netting bush. Mature stems are dark-colored; young growth is covered in downy or silky hairs (tomentum). Leaves are alternate, simple, and entire or slightly toothed, with no stipules. The indumentum is composed of characteristic T-shaped hairs. In spring, plants bear small, star-shaped yellow flowers in terminal racemes or loose clusters; flowers are bisexual and 4–6-merous, with petals bearing a membranous scale at the base. The fruit is a drupe, typically 1-seeded, and ripens red or yellow.
In habitat, corokias favor forests and rocky areas and tolerate sun or light shade with reasonably well-drained soil. The divaricating growth form — common among several unrelated New Zealand shrub genera — is widely interpreted as an adaptation to browsing pressure, historically from large moa, though this hypothesis is debated. Several species are popular in temperate gardens for their architectural form and colorful berries, and Corokia × virgata cultivars are among the most widely grown ornamental shrubs in New Zealand.
Etymology
The name Corokia is derived from the Māori word korokia, the vernacular name used in New Zealand for these shrubs.
Distribution
Corokia species are native to New Zealand (where most of the genus is concentrated, across the North Island, South Island, and Chatham Islands), eastern Australia (New South Wales and Lord Howe Island), and the remote South Pacific island of Rapa Iti in French Polynesia. The disjunct Polynesian and Australian occurrences represent the genus’s wider Gondwanan dispersal history.
Ecology
Corokia shrubs grow in forests and rocky areas, tolerating both sun and light shade. The strongly divaricating (zigzagging) branch architecture shared by several species is a growth form found in numerous unrelated New Zealand shrubs and is often linked to the island’s evolutionary history with browsing birds, particularly the now-extinct moa. Individual species occupy distinct ranges: C. buddleioides in North Island lowland forest margins, C. macrocarpa on the wind-exposed Chatham Islands, and C. carpodetoides on Lord Howe Island.
Cultivation
Several Corokia species and their hybrids — especially cultivars derived from Corokia × virgata — are widely grown as ornamental garden shrubs in temperate climates. They are valued for their architectural, angular branching, starry yellow spring flowers, and colorful red or yellow autumn berries. Plants perform best in well-drained soil in a sunny or lightly shaded position with moderate watering. Many cultivars show good wind and drought tolerance, making them popular for coastal and exposed gardens.
