It is a common weed in cool, moist forests, disturbed sites along roadsides and watercourses.
Tustan is a spreading soft-wooded shrub to about 80 cm high with distinctive rigid stems and yellow flowers.
Richardson F.J.,Richardson R.G. and Shepherd R.C.H (2006).Weeds of the south-east an identification guide for Australia. (R.G. and F.J. Richardson, Melbourne).
A rust fungus (Melampsora hypericorum) has become widely established on susceptible population in Victoria, but has not yet been released in NSW.
Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed and the plant must not be sold, propagated or knowingly distributed