The spread of Composite (Compositae) weeds in Australia

Many Composite weeds, vegetables and ornamental plants have been introduced to Australia since European settlement began in 1788. The present distribution of 4 weeds known to cause contact dermatitis is recorded on maps, and a short history of each is given. The relatively slow spread of these weeds is contrasted with the rapid spread of Parthenium hysterophorus which caused epidemic contact dermatitis in India and which has recently caused dermatitis in Northern Australia. Australian native Composite plants may play some part in the perpetuation of contact dermatitis initiated by weeds introduced into Australia.