Tamarix parviflora (smallflower tamarisk) is a shrub or a tree (family Tamaricaceae) and can be found along streams and lake shores, throughout California. Tamarix species are associated with dramatic changes in geomorphology, groundwater availability, soil chemistry, fire frequency, plant community composition, and native wildlife diversity.

Salsola tragus (Russian-thistle) is a large, bushy summer annual (family Chenopodiaceae). It can be found throughout California, including in agricultural areas, desert, roadsides and other disturbed areas. Russian-thistle can impede traffic, create fire hazards, and is a host of the beet leaf-hopper, an agricultural insect pest.

Salsola paulsenii (barbwire Russian thistle) is a bushy annual (family Chenopodiaceae) found throughout the Mojave Desert of California. It is native to southeastern Europe, central Asia. It prefers loose, sandy soils in desert scrub and disturbed areas, such as roadsides and cultivated fields. Barbwire Russian thistle is easily confused with Russian thistle (Salsola tragus), and […]

Pennisetum clandestinum (kikuyugrass) is a perennial grass (family Poaceae) that prefers disturbed areas, such as roadsides, urban areas, cropland, turf, forested sites and wetland areas. Kikuyugrass reproduces from seed and vegetatively, using its extensive system of creeping stolons and rhizomes. Kikuyugrass populations can be controlled by hand removal if detected early. Agricultural and landscape maintenance equipment […]

Ononis alopecuroides (foxtail restharrow) is a woody annual (family Fabaceae) whose current distribution in California is limited to one location in San Luis Obispo County. This Mediterranean native prefers disturbed places, such as fields and pastures, as well as grasslands and oak woodlands. Although the one known population is almost completely eradicated, foxtail restharrow has the […]

Ludwigia peploides (creeping water primrose) is a perennial aquatic plant (family Onagraceae) that forms very dense, virtually impenetrable mats which restrict fishing and boat access. It also out competes native aquatic plants. Ludwigia peploides can be found throughout California in rice fields, ditches, ponds, slow moving streams, and along edges of lakes and reservoirs. There is […]

Hydrilla verticillata (Hydrilla) is a perennial aquatic plant (family Hydrocharitaceae). It has been observed in the Mojave and Colorado deserts, south and central coasts, San Francisco Bay Area, and Central Valley. Currently, isolated infestations of Hydrilla are found in Shasta, Yuba, Lake, Calaveras, Madera, Mariposa, and Imperial counties. Hydrilla forms large mats that fill the […]

Centaurea virgata ssp. squarrosa (squarrose knapweed) is a perennial (family Asteraceae) found in the Klamath and Cascade Ranges, Modoc Plateau and northern Sierra Nevada Mountains of California. Squarrose knapweed favors disturbed open sites, including degraded rangeland, logged areas, grasslands and roadsides. Squarrose knapweed seed dispersal is enhanced by soil and water movement, and by clinging […]

Alhagi maurorum (=A. pseudalhagi)(camelthorn) is an herbaceous perennial or shrub (family Fabaceae) found in the central valley, southeastern Sierra Nevada and portions of the Mojave and Sonoran Deserts of California. It favors arid agricultural areas, grasslands, meadows and desert riparian areas. One camelthorn plant can spread rapidly (about 10 m per year in all directions) […]