A tree to 15 metres tall, forming a canopy to 10 metres wide, with light-brown to grey bark with conspicuous lenticels.
It has a wide natural distribution, occurring mainly in coastal NSW but also on the tablelands and western slopes. It extends into Queensland, up to Hervey Bay and west of Bundaberg. It also grows through much of southern Victoria to south-west of Melbourne. It has naturalised quite aggressively into habitats where it was not previously thought to grow and so some occurrences over the range may be ‘weedy’. It is a weed in Tasmania, South Australia and Western Australia.
Its natural habitat are moist gullies in rainforest and wetter sclerophyll forest. It is now found in dry sclerophyll woodlands and shrublands as well as coastal heathlands where it does not really belong. It is considered a part of vegetation types such as Turpentine Ironbark Forest and other enriched tall forests. It is found on almost all soil types.
Stems can produce some milky sap.
Pittosporum spp. have simple and alternate leaves. In this species, leaves are alternate or in pseudo-whorls (at the ends of the branches), to 15 cm long and to 4 cm wide, elliptic to narrowly obovate, glossy dark to light green with distinctive wavy or undulate margins. Most leaves will also have distinctive circular leaf miner damage along the central parts. Leaves are generally ‘sticky’ when handled and pruned and have a sickly-sweet smell when crushed.
Pittosporum spp. have 5-petaled flowers, often arranged in a variety of structures; either racemes, panicles or clusters, either terminal or axillary. In this species, conspicuously fragrant white flowers are about 20 mm long by 10 mm wide, occurring in terminal clusters with up to 10 flowers per cluster, in spring and early summer.
Pittosporum spp. have capsules although they can be fleshy and appear very much like berries. In this species, the capsules are circular to globose, orange-tan in colour and about 1.5 x 1.0 cm, containing up to 30 seeds. Seeds are about 3 mm long and reddish-brown when mature.
This species is well established in cultivation in Australia and some other warm regions around the world such as California, USA. It is a hardy and adaptable plant which appreciates most acidic soils and extra moisture, yet can also withstand extended dry periods once established. It can be clipped into hedges and is quick growing, as well as having pleasantly perfumed flowers which can pervade a large area (hence the common name ‘Native Daphne’). Many plants on the east coast of Australia flower pretty much on cue on 1 September every year and the strong odour at night is unmistakeable.
It makes a very useful shade tree. Almost no maintenance is needed once it is established.
Trees can succumb to a quick death where a lot of milky-white sap is leaked out of the stems and trunk and all the leaves quickly fall off. It is not known what causes this dieback but this Editor has observed it, from time to time, in Sydney.
Extensive notes must be given here about its weed potential: Unfortunately, the species has proven to be very invasive in bushland, colonising moist areas, such as gullies and areas of disturbed soil, as well as vegetation on sandstone ridgetops and heathlands. It will also happily colonise vegetation such as Cumberland Plain Woodland in Sydney and many other vegetation types.
It grows rapidly and quickly and shades out most other plants. The leaves have an allelopathic affect where leaf litter on the ground chemically inhibits other species from growing. Large canopies can produce very dense and wet leaf litter. It happily grows in amongst large-scale privet (Ligustrum spp.) infestations in urban Sydney and other areas.
It has become an environmental weed in Tasmania, Western Australia, Western Victoria and South Australia. It is also a weed in Cuba, as well as in bushland around Sydney. This last place is surprising in some ways as P. undulatum is an indigenous plant of the Sydney area but habitat changes brought about through urban development have been in its favour and the species has taken advantage. It is thought that it benefits from nutrient enrichment, urban run-off and lack of fire.
Growing this plant anywhere near bushland (even within several kilometres of natural bushland) cannot be recommended due to the grave environmental risk that it poses.
You could grow this plant, if desired, but ideally plants should be pruned after flowering has finished with all spent flowering parts removed.
In many cases, similar native species can be selected which will produce a similar affect such as rainforest laurels and lilly pillies.
One argument for this plant, is that it is highly favoured as habitat by ring- and brush-tail possums, which in-turn benefits threatened species such as Powerful Owls and other birds of prey. Hence, this plant might be targeted for weed removal in bushland but using a “1 in 3” or “1 in 4” culling strategy over time.
Propagation can be carried out from seed which germinates readily without treatment. Cuttings are also successful.
Pittosporum is a large genus of about 150 species, extending to Africa, southern Asia, the Pacific Islands and New Zealand. There are about 14 Australian species occurring in all states with 14 species currently occur in NSW.
This species grows in fire-prone environments and can regenerate from the seed bank and can also often reshoot from suckers and trunk-buds.
Pittosporum – from Ancient Greek – although not overly clear, there is information that the words pitta (πίττα) and pissa (πίσσα) were used to refer to “pitch” (tar / bitumen), and –sporum (sporos, σπόρος) means “seed”, referring to the sticky resinous nature of the seeds. The words pitta and pissa may also be connected to “pizza” and “pita”, early words used to refer to unleavened bread.
undulatum – from Latin undulato – meaning “wavy”, referring to the characteristic wavy or undulate edges of the leaves.
This species is not considered to be at risk of extinction in the wild.
Australian Native Plants Society Australia – Pittosporum undulatum profile page
Plants of South Eastern New South Wales – Pittosporum undulatum profile page
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.