Erigeron canadensis is an annual, herbaceous plant growing to 1.5 metres (5 feet) tall, with sparsely hairy stems.

The leaves are unstalked, slender, 2–10 centimetres (0.8–3.9 inches) long, and up to 1 cm (0.4 in) wide, with a coarsely toothed margin.

[9] It is found in Britain from northern Scotland to Cornwall, growing as a weed of arable land and man-made environments.

[17] Farmers are advised to include 2,4-D or dicamba in a burndown application prior to planting to control horseweed.

Native Americans have used a preparation of the plant's leaves to treat sore throat and dysentery.

[citation needed] Horseweed is a preferable material for use in the hand drill-method of making friction fire.