A form with rayless flowers is sometimes considered a separate species.
Grindelia squarrosa, also known as a curly-top gumweed or curlycup gumweed, is a small North American biennial or short-lived perennial plant which grows to a maximum height of 90 cm (appx. 3 ft) and bears flowers with yellow petals from July until late September. It was used by Great Plains Tribes as a medicinal herb to treat illnesses such as asthma, bronchitis or skin rashes.
The Gosiute Shoshone name for the plant is mu’-ha-kûm.