Rust fungus gall

Description:

A multi-lobed rust brown woody growth on a branch of an acacia tree. The surface of the the growth was slightly powdery.

Habitat:

Acacia wattle

Notes:

These growths are a commonn sight on acacia trees. They are galls formed by a fungus and the reddish colour on the outside are spores of the fungus. The galls formed are sometimes inhabited by beetles and moths. The web reference has interesting information on these galls.