Spreads quickly

A coarse, branched herb between 20 cm and 2 metres tall originally from Central and West Africa. Brillantaisia is an invasive weed in tropical Australia. It was thought that the subtropical climate of Brisbane was out of this plant’s preferred range until several infestations were discovered in the Toowong Mount Coot-tha area including Walton Bridge Reserve, The Gap. In 2025, serious infestations were seen along Enoggera Creek in areas disturbed by flooding. Opposite, heart-shaped leaves and stems that are hairy and square. Brilliantasia likes to grow in moist areas full sun of part shade. It can form dense thickets that can crowd out native vegetation and reduce food sources for wildlife. It can spread quickly through riparian and disturbed areas. The flowers are a bright blue to purple and the seed pods are long and cigar shaped. Brilliantasia reproduces by both seeds dispersal and rooting from stem fragments.

Photo: Sheldon Navie

Foliage and flowers. Photo: Robert Whyte

Flower close-up. Photo: Sheldon Navie