Pittosporum crassifolium, commonly called Karo, is a small tree or shrub native to New Zealand. Karo's original distribution was generally the top half of the North Island, although now it has naturalised throughout New Zealand and overseas in Norfolk Island and Hawaii. P. crassifolium occurs in lowland and coastal forests. Mature trees grow to about 5 metres (16 ft) in height. Other common names include stiffleaf cheesewood, and in Māori, kaikaro and kīhihi.