Have you seen Australian cheesewood (Pittosporum undulatum)?
Hawaii Early Detection Network Priority Pest for the island of Maui


Australian cheesewood  sapling
Sapling in Kula, Maui
Australian cheesewood  detail
Fresh fruit pod and dried fruit pod (inset)
Australian Cheesewood flower
Flower detail
Images: Forest & Kim Starr

Identification: Australian cheesewood, aka Victorian box and sweet pittosporum, is a fast growing evergreen tree that is often grown in gardens for its aromatic white flowers. It can grow from 15' to 45' and has shiny green leaves that are 2'' to 6'' long with distinctly undulating edges. Leaves have an alternate arrangement. Five-petal white flowers (3/4'' - 1'' long) are found clustered at the ends of young branches and smell strongly of citrus. Orange fruit capsules are formed in the fall (.6'' long) that contain shiny black seeds.
Impacts: Australian cheesewood is a popular landscaping tree that has escaped the garden in Hawai'i, Jamaica, South Africa, New Zealand and other Pacific and Atlantic Islands. This tree is considered the most threatening invasive plant in the Blue & John Crow Mountains of Jamaica, where it outcompetes native plants in the tropical montane forest. This tree has aggressive growth rates, with up to 5,000 seedlings per m2 in infested areas. The seeds that are eaten and distributed far distances by birds.
Dispersal Mechanism: Australian cheesewood is spread by humans who use the plant in landscaping. It readily escapes the garden and is further spread by fruit eating birds.
Origin, Distribution, and Habitat: This tree is native to Australia, but is widely cultivated throughout the world as an ornamental plant. In Hawai'i, Australian cheesewood has naturalized in disturbed mesic forests on Lana'i and Hawai'i where it covers large acreage and often dominates areas it invades. On Maui, it is only known from a few trees which were removed by the Maui Invasive Species Committee, see map).

More information about this pest external link


Ho'awa(Pittosporum spp.):
There are 10 endemic pittosporum in Hawai'i, found in a variety of habitats, but usually associated with predominantly native forests. Australian cheesewood can be differentiated by its undulating edged leaves.

ho'awa
Ho'awa (Pittosporum glabrum)
primrose
Cape pittosporum

Cape pittosporum(Pittosporum viridiflorum):
This tree is native to South Africa, and is also cultivated in Hawai'i for garden plantings. This tree also has fragrant, orange scented flowers and orange seedpods, but does not have the undulating leaf margins. This tree may be a pest also, according to the Hawaii Weed Risk Assessment, as it readily naturalizes. It is actively removed from the island of Maui by the Maui Invasive Species Committee.

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