Pittosporum crassifolium Banks & Sol. ex A. Cunn.
dwarf karo, karo, karo pittosporum, stiff-leaf cheesewood, stiffleaf cheesewood, thick leaved box
Native to New Zealand (i.e. the North Island of New Zealand and the Kermadec Islands).
Naturalised in south-eastern Australia (i.e. in southern Victoria and the coastal districts of central New South Wales). Also sparingly naturalised in south-eastern South Australia and naturalised on Norfolk Island.
Naturalised overseas in south-western USA (i.e. California).
Karo (Pittosporum crassifolium) is regarded as an environmental weed in Victoria and New South Wales, and as a "sleeper weed" in other parts of southern Australia. This species is cultivated as a garden ornamental in wetter temperate regions, where it is often grown as a hedging plant. Its fruit are eaten by birds and other animals, which spread it into bushland areas.
Karo (Pittosporum crassifolium) is most important in Victoria, where it is seen as a potential threat to one or more vegetation formations. It was first recorded becoming naturalised in this state in 1984 and is now regarded as a potentially serious environmental weed. It appears on several local environmental weed lists in the southern parts of Victoria (e.g. in the Shire of Yarra Ranges, Mornington Peninsula Shire, Colac-Otway Shire and Sherbrooke Forest) and is listed as a "sleeper weed " in Frankston City.