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 […]

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 […]

Isatis tinctoria (dyer’s woad) is a winter biennial or short-lived annual herb/forb (family Brassicaceae). Plants are highly competitive and often grow in dense colonies. It can be found distributed among the Klamath, Cascade, and North Coast Ranges, northern & central Sierra Nevada, Modoc Plateau, and northern San Francisco Bay region. Dyer’s woad is a noxious […]

Myosotis latifolia (common forget-me-not) is a perennial or annual herb (family Boraginaceae) found primarily in coniferous and riparian areas along the coast in northern and central California. It is native to northwestern Africa and was introduced into North America as a garden ornamental. Common forget-me-not is low-statured, with pale blue to pink radiate flowers in […]

Mesembryanthemum crystallinum (crystalline iceplant) is a low-growing annual or biennial succulent shrub (family Aizoaceae) found on coastal bluffs of the California coastline and the Channel Islands. It is native to South Africa, but has been used as a landscape ornamental.  It is named for the small glistening vesicles that cover its leaves and stems. Crystalline […]

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.

Marrubium vulgare (white horehound) is a perennial shrub/forb/herb (family Lamiaceae). This plant is found heavily populating disturbed places throughout California in grasslands, scrub, and riparian areas. It has mostly minor impact on native species.

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 […]

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.