About Pittosporum angustifolium G.Lodd.
Pittosporum angustifolium G.Lodd. is a weeping shrub or tree that grows up to around 10 m (33 ft) tall. It has thick, fissured bark that is fibrous or flaky in texture. Its leaves are arranged alternately along stems, and shaped oblong, linear, or narrowly elliptic. The leaves are curved, measure 50–90 mm (2.0–3.5 in) long and 6–11 mm (0.24–0.43 in) wide, and grow from a petiole 5–14 mm (0.20–0.55 in) long.
Flowers of this species are dioecious, arranged singly, in small groups in leaf axils, or in clusters at the ends of branches. Each flower sits on a pedicel 5–12 mm (0.20–0.47 in) long. Male flowers grow in groups of four, have a small pistil, and stamens that are 5.5–6.0 mm (0.22–0.24 in) long. Female flowers have an ovary roughly 5 mm (0.20 in) long, with a short style. Flowering occurs mostly from winter through spring.
The fruit is an oval to spherical yellowish capsule 8–14 mm (0.31–0.55 in) in diameter, containing sticky, reddish-brown seeds that are 4–5 mm (0.16–0.20 in) long.
This species is widespread across Australia, occurring in every state except Tasmania, as well as the Northern Territory, and is found mostly in inland parts of the country. It grows in mallee communities, on alluvial flats and ridges, in dry woodland, and in loamy, clay, or sandy soils, but it is never a common species. It is resistant to drought and frost, and can survive in areas with as little as 150 mm (5.9 in) of annual rainfall. As a resilient desert species, individual plants may live for over 100 years.
Pittosporum angustifolium is used as an ornamental garden plant, valued for its weeping growth habit and orange fruit. Indigenous Australians have used parts of this plant for various purposes, including medicine, with uses varying between regions and communities. Some groups ate or chewed the gum that oozes from the plant's branches, while others ground its seeds into flour to use as food. Most commonly, leaves, seed, or wood were steeped in hot water to make a poultice or tea for medicinal use, to relieve digestive issues, internal pain and cramping, reduce chronic fatigue, induce lactation, treat colds, muscle sprains, eczema, and other causes of itching. Despite being commonly called "native apricot", the bitter fruit is very rarely used as a food source.
Ongoing international scientific research has begun to identify medically relevant biochemistry in P. angustifolium, including antimicrobial, antibacterial, antioxidant, antifungal, anti-inflammatory, and galactogogue compounds. Study findings indicate that biochemical compounds from this plant have low toxicity when consumed by humans. These compounds may be able to inhibit microbial and fungal growth, induce lactation, trigger apoptosis in cancer cells, protect cells against free radicals and oxidisation, and increase the efficacy of commonly prescribed antibiotics. These findings align with the plant's traditional uses and Indigenous knowledge.
Central Queensland University ran a long-term project to investigate the potential medicinal uses of native Australian plants, in consultation with Ghungalu elder Uncle Steve Kemp, who provided plant material including P. angustifolium for the project. Cytotoxic, antioxidant, and phenolic compounds have been identified in the species, strongly supporting the therapeutic benefits and potential anti-cancer properties of the plant. Other studies have also identified cytotoxic properties in this species.
