A potentially large tree (usually growing slowly), up to 40 metres tall with an upright erect canopy and with a trunk potentially reaching over 70 cm in diameter. The bark is greyish brown, not smooth and irregular.
In NSW, it is only found on the North Coast subdivision (although has been planted extensively elsewhere), north from the Coffs Harbour region, through Grafton and Lismore. It grows in Queensland through the Gold Coast, Brisbane and the Sunshine Coast towards Gympie with disjunctions near Hervey Bay, west of Mackay and the Cairns region (with the furthest northern records west of Cape Tribulation).
It grows in sub-tropical and tropical rainforest, usually on enriched soils.
Stenocarpus spp. have simple leaves or leaves which are heavily lobed to appear compound, and are arranged alternately. In this species, the leaves are simple, but are highly variable, varying between oblong-lanceolate with an unlobed margin, or with margins strongly and irregularly lobed, forming a shape similar to that seen in some oak trees, to 25 cm long and 10 cm wide, dark green with a leathery texture, with upper surface shiny and lower surface dull and only 1 main midvein present.
Stenocarpus spp. have flowers typical of the Proteaceae family with 4 tepals, 4 stamens and 1 carpel. In this species, flowers are very showy, with up to 20 bright red flowers arranged in an umbel, appearing at the branch terminals, and with flowers radiating around a disc-like structure so as to appear circular (i.e. “fire-wheels”), appearing mostly between February to March. Flowering can be very dramatic.
Stenocarpus spp. produce a follicle. In this species, it is boat-shaped, to 10 cm long. Inside are many thin seeds to 25 mm long, maturing from January to July.
This has been a very popular and successful tree in cultivation. Cultivated trees are often marked by their narrow erect canopy in many young trees.
Despite its sub-tropical to tropical origin, S. sinuatus is adaptable to a range of climates and will even succeed in dry climates if additional water is available.
They are readily seen in council landscapes as well as botanic gardens.
In a garden situation, it grows at its best in a fairly rich, loam soil but is tolerant of most well drained soils. It may be grown in a sunny or partly shaded location.
This author planted this tree 40 years ago in his northern Sydney garden, in a full sun position, in a clay based soil that dries out in Summer. It has never flowered and has been slow growing to 8 metres (a tall and skinny tree). In 2021/22, Sydney had much higher rainfall and humidity than usual, which resulted in the plant producing a growth spike and many repeat flowers. The only problem is the flowers are now at the top of this tree and hard to see. As well, seedlings appear under this tree. These could possibly be transplanted or potted up.
Give it some room to spread out. Good for attracting birds and insects.
Fresh seeds germinate rapidly, cuttings also strike well. Plants grown from seed may take 7 years or more to flower. Cutting-grown plants propagated from mature flowering plants will usually flower in 3 to 4 years.
The Firewheel tree takes its name from the configuration and colour of the inflorescences in which the small flowers have a wheel-like arrangement. It is one of Australia’s most spectacular trees.
Stenocarpus is a genus of about 25 species, Twelve species are endemic to New Caledonia. Australia has 10 species, 8 of which are endemic, occurring in New South Wales, Queensland, the Northern Territory and Western Australia. A further two species, S. moorei and S. sinuatus also occur in New Guinea and the Aru Islands. NSW currently has 2 species.
The genus Stenocarpus was first formally described in 1810 by Robert Brown in the Transactions of the Linnean Society of London
This species can regenerate from fire from the seedbank and may be able to produce coppicing or suckering growth. Species in this genus are not reported to have lignotubers.
Stenocarpus – from Greek – Stenos (στενός) – meaning “narrow” and karpos (καρπός) meaning “fruit” – referring to the long follicles of most species.
sinuatus – Latin meaning “sinuate” or “sinuous” – referring to the wavy leaf margins of many leaves.
This species is not considered to be at risk of extinction in the wild.
Australian Native Plants Society Australia – Stenocarpus sinuatus profile page
https://anpsa.org.au/plant_profiles/stenocarpus-sinuatus/
NSW Flora Online (PlantNET) Stenocarpus sinuatus profile page:
https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Stenocarpus~sinuatus
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.