Species: H. congesta
Hemizonia is a genus of plants in the daisy family (Asteraceae). They are known generally as tarweeds, although some tarweeds belong to other genera, such as Madia and Deinandra. Furthermore, Hemizonia is currently being revised; some species may be segregated into new genera.
The Hemizonia tarweeds are native to southwestern North America, especially California.
Hemizonia are usually sticky, aromatic, yellow-flowered annual plants which are hardy and competitive, especially in the dry Mediterranean climate of California.
* Hemizonia arida – Red Rock Tarweed
* Hemizonia clementina – Catalina Tarweed; Santa Catalina Island, California
* Hemizonia congesta – Hayfield Tarweed
* Hemizonia conjugens – Otay Tarweed; Otay Mesa, San Diego, California area.
* Hemizonia fitchii – Fitch's Tarweed
* Hemizonia floribunda – Tecate Tarweed
* Hemizonia frutescens
* Hemizonia greeneana
* Hemizonia kelloggii – Kellogg's Tarweed
* Hemizonia lobbii – Threeray Tarweed
* Hemizonia minthornii – Santa Susana Tarweed; State and CNPS listed vulnerable species in the Simi Hills, Santa Susana Mountains, and Santa Monica Mountains areas.
* Hemizonia palmeri
* Hemizonia paniculata – San Diego Tarweed
* Hemizonia pungens – Common Tarweed
* Hemizonia streetsii