Deinandra

Deinandra is a genus of plants within the Asteraceae, or sunflower family. These plants are commonly known as "deinandra," "oilweed," or "tarweed," although the name "tarweed" is often applied broadly to several other related genera within the Madiinae subtribe.

Deinandra species are native to western North America, primarily California and adjacent areas. They are characterized as annual or perennial herbs, often with a sticky, resinous coating that gives them their common name (tarweed) and distinctive odor. The sticky resin is produced by glandular trichomes (hairs) on the leaves and stems.

These plants typically have alternate leaves and produce yellow ray and disc flowers in heads. The morphology of the involucral bracts and the cypselae (achenes or "seeds") are important characteristics used in Deinandra species identification.

Deinandra species occupy a variety of habitats, including grasslands, chaparral, and open woodlands. Some species are adapted to serpentine soils, which are nutrient-poor and high in heavy metals.

The taxonomy of Deinandra and related genera in the Madiinae has been subject to revision based on molecular and morphological evidence. Some species previously classified in Deinandra have been moved to other genera, and vice versa. This taxonomic fluidity can make identification challenging.

Several Deinandra species are of conservation concern due to habitat loss and other threats.