It grows to a height of 1.5 to 2.0 m under favourable conditions, but plants may mature and set seed at heights of only 10 cm under dry conditions. The leaves are greyish-green, deeply lobed and covered with short hairs.
Stems are also hairy.
Creamy-white flower heads about 4 mm in diameter are produced in clusters at the end of each branch. Each flower head produces about 4 black seeds, which are approximately 2 mm in length with two thin, white, spoon-shaped appendages. In 1964 it was again reported north of Clermont, Queensland, where it was introduced in contaminated grass seed from the United States. It has since spread through central Queensland and New South Wales. In August 1977, parthenium was discovered in the Northern Territory along Elsey Creek in the Mataranka district.