Nicotiana glauca (tree tobacco) is a tree/shrub (family Solanaceae), which stands 10-20 feet tall and is short-lived. Tree tobacco was introduced to California about 100 years ago and is found growing up to 5,000 feet in disturbed soils, vacant lots, along roadsides, streamsides, and other riparian areas.

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 […]

Nassella manicata (tropical needlegrass) is a perennial (family Poaceae) found in Northern California.

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.

Myriophyllum spicatum (spike watermilfoil) is a common submersed aquatic perennial (family Haloragaceae). Spike watermilfoil can be found in freshwater lakes, ponds, and canals with slow-moving waters in northern and central California, particularly in the San Francisco Bay and San Joaquin Valley regions and Lake Tahoe. This plant grows and spreads rapidly, creating dense mats on […]

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 […]