Mentha pulegium (pennyroyal) is a perennial mint (family Lamiaceae) with a variable habit, ranging from low-growing, spreading plants to lanky, upright sub-shrubs. Although considered uncommon in much of California, pennyroyal occurs in the Sierra foothills, Central Valley, and most coastal counties from the Mexican border to Oregon. It is common as an obligate wetland indicator […]

Medicago polymorpha (California burclover) is a perennial/annual forb/herb (family Fabaceae) found throughout California in disturbed areas such as pastures, roadsides and vacant lots. Although it is considered good forage for livestock in pastures, it can out-compete native species in natural areas. Despite its name, California burclover is native to the Mediterranean.

Myoporum laetum (ngaio tree) is an evergreen shrub or small tree (family Myoporaceae) found along the coast of California and in the San Francisco Bay region. It favors coastal areas, woodlands and riparian areas. This landscape ornamental has white flowers with purple dots and reddish-purple fruits. Ngaio tree has escaped cultivation in many areas, and […]

Lythrum hyssopifolia (hyssop loosestrife) is a perennial forb/herb (family Lythraceae) that invades wetlands. It occurs in seasonal wetlands, ditches, and cultivated fields, especially rice fields. L. hyssopifolia often grows on exposed mud, tolerates some salinity, but is sensitive to heavy frost.

Ludwigia hexapetala (Uruguay waterprimrose) is an aquatic plant (family Onagraceae) that forms dense mats in waterways, reaching above and below the water surface. This dense growth impedes water movement, blocks the growth of native plants, and reduces available habitat for waterbirds and fish. Although this species has been naturalized in California for at least 25 […]

Lobularia maritima (sweet Alyssum) is a perennial (family Brassicaceae) found along the coast of California and in the San Francisco Bay area. Sweet Alyssum is a common ornamental plant that has escaped cultivation and invaded disturbed coastal dunes, scrub, bluffs, prairies and riparian areas. It has a long flowering season, and appears to have the […]

Linaria vulgaris (yellow toadflax, butter and eggs) is an herbaceous perennial (family Plantaginaceae) that was introduced as an ornamental. It can be found in disturbed open sites, fields, pastures, degraded rangelands, roadsides, agronomic and perennial crops. Although it is typically found in northern California, it can occur sporadically in many other areas of California, except […]

Lythrum salicaria (purple loosestrife) is a wetland herb (family Lythraceae) that invades scattered freshwater wetlands of northern and central California. Infestations are found in northern California and the San Francisco Bay Area, as well as along rivers in the southern Sierra. It is a hardy perennial that can rapidly degrade wetlands, diminishing their value for […]

Limnobium spongia (South American spongeplant) is a perennial aquatic plant (family Hydrocharitaceae) found on the San Joaquin river and the Sacramento-San Joaquin delta. The spongeplant can form thick mats across the water causing problems for boats, fish, and water infrastructure. Limnobium spongia can spread rapidly through quick seed production and vegetative growth. The small, floating […]

Leucanthemum vulgare (ox-eye daisy) is a perennial forb/herb (family Asteraceae). It is commonly sold at nurseries. Ox-eye daisy is found in both the North Coast Range and northern Sierra Nevada from sea level bluffs and canyons to alpine mountain meadows at 7,000 feet (2200 m), and from central California to Oregon. Ox-eye daisy displaces native […]