[1] It is native to Brazil, Argentina, and Uruguay, and it is present elsewhere as an introduced species and roadside weed.

[2][3] It is an annual or perennial herb producing one or more stems growing decumbent to erect in form and hairy to hairless in texture.

The rough-haired leaves are divided deeply into lobes.

The inflorescence is a dense, headlike spike of many flowers up to 1.5 centimeters wide.

[4] Each flower corolla is up to 1.4 centimeters wide and white to purple in color.