Attractive crimson flowers

Brachychiton acerifolius is widely planted in gardens and in bushcare sites. Strictly speaking it has not been considered an Enoggera species, not being recorded in D’Aguilar National Park. However it was recorded in The Gap Rainforest survey published 2023. Its range is coastal rainforests from central New South Wales to far north Queensland. May reach 30-35 metres in height although it is usually much smaller in cultivation in cooler areas. Brachychiton from Greek, brachys, short and chiton, a tunic, a reference to the coating on the seed. Acerifolius having foliage like the genus Acer (maple). Acer means star in Latin. Leaves are about 250 mm long and may have entire margins or be deeply lobed. Its popularity stems from its attractive crimson flowers and its green trunk. It is commonly planted as a park and street tree in Brisbane. Tim Low writes in Bush Tucker that the seeds are edible and “it is easy to gather seeds from roadside trees to roast as treats”.

Photo: Robert Whyte

Flowers

Generally deciduous before flowers are seen in early summer. The bell-shaped flowers occur in clusters at the ends of the branches. In some seasons foliage will be retained on all or part of the tree. Flowering may take around 5-8 years from seed. Hardy in a wide range of soil. Host to butterfly larvae of Common Aeroplane Phaedyma shepherdi, Tailed Emperor Polyura sempronius, Common Pencilled-blue Candalides absimilis and Hairy Line-blue Erysichton lineata.

Photo: Robert Whyte

Host plant for bugs

The insects congregating in the seed pods in this picture are probably the Cotton Harlequin Bug Tectocoris diophthalmus. They normally feed on the Malvaceae such as the Native Hibiscus Hibuscus heterophyllus but references notes three Brachychiton hosts in Sterculiaceae including B. acerifolius.

The Pentatomoidea Home Page cites:

• Cassis, G. and L. Vanags. 2006. Jewel bugs of Australia (Insecta, Heteroptera, Scutelleridae).
• Rabitsch, W. (ed.), Hug the Bug: For Love of True Bugs. Festschrift zum 70. Geburtstag von Ernst Heiss. Denisia 19:275-398.)

Bugs congregating in the seed pods. Photo: Rick Caskey

Seed collecting and propagation

The seed pods appear in late summer and early autumn. Collect the pods and process using gloves as the seeds are surrounded by irritant hairs. Remove seed from follicle. Use 24-hour hot water soak. Sow seeds directly into pots. Germination of sown fresh seed may be erratic, starting as early as 5 days but commonly requiring 140 days for final germination of 90%. Cuttings and grafts are also successful particularly as these trees may flower more quickly. If sown from seed flowering may take around 5-8 years or longer for a mature display.