Torilis arvensis (hedgeparsley)  is an annual forb (family Apiaceae) that occurs across many habitats throughout California, with exception of deserts and higher elevation habitats. It is native to central and southern Europe. Hedgeparsley  is generally a small-statured, slender plant, rarely growing up to 1m height. Leaves are pinnately dissected; leaflets have toothed edges. Flowers are […]

Tamarix aphylla (athel tamarisk) is a shrub or a tree (family Tamaricaceae) found along streams and lakeshores throughout California. Tamarix aphylla and other tamarisk species were introduced as landscape ornamentals. Athel tamarisk is still widely planted as an ornamental species in southern California but is less invasive than other tamarisk species. It has escaped cultivation […]

Zostera japonica (=Nanozostera japonica, dwarf eelgrass) is an aquatic plant that forms dense stands in shallow, sheltered bays and estuaries. Populations of Z. japonica have been found in Humboldt County. Z. japonica often invades areas with little or no natural or human disturbance and also shows a positive relationship with disturbance. Z. japonica lives as […]

Undaria pinnatifida (wakame) is an annual algae (family Alariaceae) first recorded in several estuaries in California in 2000. Wakame is native to Japan, where it is consumed for its food value and as a nutritional supplement. In California, wakame usually cannot compete with native perennial brown algae, but it may colonize estuaries rapidly if native […]

Verbascum thapsus (common mullein, woolly mullein) is a biennial or annual forb (family Scrophulariaceae) that occurs throughout California, but is particularly abundant in dry valleys on the eastern side of the Sierra Nevada. High population densities have been observed in moist meadows and creek drainages near Mono Lake and Owens Valley. Common mullein is a […]

Vinca major (periwinkle) is a spreading perennial vine or ground cover (family Apocynaceae) with dark green stems that contain milky latex. In California it is rapidly spreading in most coastal counties, foothill woodlands, the Central Valley, and even desert areas. Periwinkle has escaped from garden plantings, and lowers species diversity and disrupts native plant communities. […]

Festuca myuros (rat-tail fescue) is an annual grass (family Poaceae) widely distributed in California. This species is one of many introduced annual grasses that reduces habitat for native perennial grasses.

Washingtonia robusta (Mexican fan palm) is a single-trunked palm tree (family Arecaceae) found in the San Francisco Bay area, southern Sacramento Valley and on California’s south coast. It is native to semi-arid landscapes of northwestern Mexico, including Baja California. Mexican fan palm is a common landscape ornamental that has become invasive in riparian areas, orchards […]

Watsonia meriana (bulbil Watsonia) is a perennial flowering herb (family Iridaceae) found in disturbed areas, coastal prairies and coniferous forests along the northern coast of California. This corm-forming, ornamental, South African native reproduces by growing bulblets. Bulbil Watsonia, which is generally avoided by wildlife as a food source, forms dense patches that may crowd out […]

Zantedeschia aethiopica (calla lily) is a perennial (family Araceae) found along the coast of California, in the North and South Coast Ranges, and in the San Francisco Bay area. Native to South Africa, calla lily is grown as an ornamental plant, and most invading populations are found near human habitations in coastal prairies and wetlands. […]