"Tree to 30 m tall,..." (Flora of Australia Online)

Cassia brewsteri is found in open forests, woodlands and scrubs and is also seen as a garden specimen or street tree. Considering the intense beauty of this tree when in flower and its shade giving qualities, it could certainly be cultivated more often and be considered as a replacement for weedy trees. The hard-coated seed has been a common item on mine rehabilitation species lists in central Queensland. Seed collectors have a sizeable window after December each year to harvest. Seed crops will at some point be parasitised and fed upon, possibly by a type of weevil larvae, to the point of making collection uneconomic.

Previously, Cassia brewsteri was considered to have the varieties C. brewsteri var. tomentella and C. brewsteri var. marksiana. These are now named species. Cassia tomentella (see also on this website) is used in rehabilitation of some mines. C. marksiana occurs in south-east Queenland and in New South Wales. It is listed as an endangered species in NSW.

C. brewsteri may confuse workers and those looking for it because the height of the tree varies greatly. In the drier open woodlands near Emerald for example it is usually just several metres in height or maybe twice that around gullies. Near Gympie and Maryborough it may be more than 20m high.

Flora of Australia Online. Australian Biological Resources Study, Canberra. [Date Accessed: Oct 28, 2019] http://www.ausflora.org.au

https://profiles.ala.org.au/opus/foa/profile/Cassia%20brewsteri%20var.%20brewsteri