Grindelia robusta is native to California and Baja California, where it can be found in a number of habitats. Its range may extend into Nevada.

description
Grindelia robusta, a member of the Asteraceae family, is a gangly weedy perennial topping two meters in maximum height. Its erect, branching stems are lined with many stiff, wavy-edged, serrated leaves 2 to 3 cm long. Atop the stem branches are inflorescences of a single large flower head up to 3 cm wide. The head is a vaguely thistle-like cup of green claw-like phyllaries that bend downward. The centre of the head is filled with yellow disc florets and there are usually many yellow ray florets around the circumference. The flower head fills with a copious white exudate, especially during the early stages of blooming.

common names & nomenclature
The origin of this plant's scientific name epithet robusta means "robust". The common names like Gumweed, Gumplant, Tarweed and the like are all in reference to the resin that comes from the plant.

Also known as:
gumplant, gumweed, tarweed, great valley gumweed, great valley gumplant, grindelia camporum, boton de oro

climate
Grindelia is a hardy plant readily grows in disturbed and altered areas such as ditches and roadsides in full sun.

soil
Will grow in any well-drained soil, on dry sandy banks and in poor soils.

growing
Sow seeds in autumn or spring in a cool greenhouse and only just cover the seed. Transplant the seedlings into individual pots when they are large enough to handle and plant them out into their permanent locations in early summer.

harvesting
Harvest the leaves and flowers of grindelia anytime during the season, use fresh or cut into pieces and dry for later use.

preserving
Store dried grindelia in an airtight container in a cool, dry place.