Stenocarpus sinuatus

firewheel tree

 

Stenocarpus sinuatus

(A.Cunn.) Endl. 1848

pronounced: sten-oh-KAR-puss sin-yoo AR-tuss

(Proteaceae — the waratah family)

 

common name: firewheel tree

native 4Stenocarpus is derived from the two Greek words, στενος (stenos), narrow, and καρπος (karpos), fruit, referring to the characteristics of the seed capsules; sinuatus is Latin for wavy, referring to the leaf margins.

The is an Australian rainforest tree, distributed naturally from the Atherton Tableland (17°S) in North Queensland as far south as the Nambucca River (30ºS) in NSW. The tree also occurs in Papua New Guinea. It is widely planted as an ornamental tree in many other parts of Australia (it does very well in the high humidity of the Sydney area, and will happily grow as far south as Melbourne), and in other countries. The tree photographed is in a Picnic Bay garden.

It grows into a medium-large tree, up to 40 m tall, with a trunk diameter of 75 cm, although it rarely exceeds 10 m in height when grown in gardens. The bark is a greyish brown in colour, quite rough and irregular, and the base of the trunk is flanged. The lower branches tend to be horizontal, but ascend towards the apex of the tree.

The foliage is quite dense and attractive. Individual leaves are normally bright dark green and display a glossy upper surface with the under-surface a pale green. The leaves are alternate, and very irregular in shape, varying from simple to pinnatifid, with the leaf margins wavy, as suggested by the specific. As with many proteaceous plants, the leaves may change their shape at will. They are usually 15 - 25 cm long, but can be up to 45 cm long, and are 2 - 5 cm wide. One reason for the tree’s popularity is its distinct autumn foliage, especially in areas where autumn leaf colours are rare. The leaves show various colours from yellow to orange and ruby-red and crimson; the timing of the colour change varies from area to area and from tree to tree, adding an unpredictability to the autumn display.

Flowering may occur anytime from 10 to 15 years of age and can be sporadic until the tree is older. The flowers are terminal or nearly so, bright red and symmetrical like the spokes of a wheel. Characteristically they occur on old wood in umbels of 6 to 20. Individual flowers may be up to 10 cm in diameter. Normal flowering takes place from summer to autumn though odd flowers may occur when induced by high rainfall and humidity.

The fruit is a boat-shaped follicle, 5 - 10 cm long, grey-brown in colour, with short hairs, and containing many thin seeds.

Propagation is from fresh seed, which germinates readily. Cuttings are also viable.

The tree produces beautifully grained red timber, much sought-after by early settlers for brake-blocks, building framing and flooring. The wood is also suitable for cabinet-making.

Larvae of the Double-headed Hawk moth Coequosa triangularis feed on this tree.

 

Photographs taken in Picnic Bay 2016
Page last updated 8th April 2019