Potato weed (Galinsoga parviflora) is a warm-season erect annual herbaceous plant, native to Central America. It grows up to 0.6 metres in height, but is usually about 0.3 metres in height.
Leaves are opposite, symmetrical, between 1.0-11.0 cm in length and 0.5- 7.0 cm in width, oval shaped, moderately hairy, with wavy margins. Cotyledon leaves are rounded with a slightly indented tip. Flowers are yellow with white to dull pink petals, 3.5-5.0 mm in length and 2.0-6.0 mm in height. There are two types of flowers: disc flowers, forming the central portion of the flower head; and ray flowers, giving the appearance of a single petal and forming a ring around the disc flower. Potato weed may also be known in parts of Australia as 'yellow weed'. It is named for its broad resemblance to potato plants.
Most vegetable farmers will be well aware of potato weed and how to identify it. It closely resembles 'hairy Galinsoga' (Galinsoga quadriradiata), though at the time of writing that species did not appear to be present in Australia. Depending on stage of growth and experience in identification, some other common annual heavy-seeding weeds of Australian vegetable production may be mis-identified as potato weed, including fat hen (Chenopodium album), amaranth (Amaranthus spp.), or blackberry nightshade (Solanum nigrum).