Fallopia sachalinensis (Sakhalin knotweed) is a perennial forb/herb (family Polygonaceae). Plants grow vigorously and create dense colonies that exclude other vegetation. Established colonies are extremely difficult to eradicate. It inhabits disturbed moist sites, roadsides, riparian and wetland areas. Plants typically grow in open, sunny areas on moist soils in cool temperate climates. Very little of this […]

Polypogon monspeliensis and subspp. (rabbit foot Polypogon, annual beardgrass) is a winter or summer annual grass (family Poaceae), It is native to Europe, Asia, and northern Africa, and introduced into other parts of Africa, Australia, various islands, and North and South America.  Plants are variable in height, growing from 5 cm – 1 m. Leaves […]

Potamogeton crispus (curlyleaf pondweed) is an aquatic perennial (family Potamogetonaceae). The genus Potamogeton contains many widespread, variable species that are difficult to tell apart. Potamogeton species are important for wildlife, but they can become problems in managed aquatic systems such as irrigation canals. All species of Potamogeton are native to California except P. crispus. There […]

Ranunculus repens (creeping buttercup) is a spreading perennial forb/herb (family Ranunculaceae), found in many coastal areas of California. It can sometimes form large monocultures, especially in moist areas.

Raphanus sativus (wild radish) is an annual or occasionally a perennial (family Brassicaceae) that frequently invades grasslands and open/disturbed areas, including roadsides in California. Wild radish may also be found in wetland areas. Wild radishes are capable of excluding native plant species and are, on rare occasion, toxic to livestock.

Ricinus communis (castor bean) is an semi-woody large shrub (family Euphorbiaceae). Native to the southeastern Mediterranean, eastern Africa, and India, it has escaped cultivation and established outside of its historic range to become a noxious weed in many mild climates, including in southern and central California. It has a shrubby habit but can reach the […]

Robinia pseudoacacia (black locust) is a deciduous tree (family Fabaceae) that grows to 100 feet tall. Historically planted as a landscape tree, black locust has escaped cultivation and become invasive in California and elsewhere. It can grow on a wide range of sites, but grows best on rich, moist, limestone-derived soils. It does not do […]

Rubus armeniacus (Himalayan blackberry), formerly known as Rubus discolor, is a sprawling, essentially evergreen, glandless, robust shrub (family Rosaceae). Rubus armeniacus occurs in California in the coast ranges, Central Valley, and Sierra Nevada. This weed is a strong competitor. It rapidly displaces native plant species and thickets to produce such a dense canopy that the […]

Rumex acetosella (red sorrel, sheep sorrel) is a perennial forb/herb (family Polygonaceae). In California, sheep sorrel occurs in a freshwater marsh community and is common in annual grasslands, montane meadows and perennial bunchgrass communities.

Prunus cerasifera (cherry plum) is a deciduous tree (family Rosaceae). It is an ornamental plant that has escaped cultivation, so it is often found near towns and along roadsides, as well as in chaparral, woodland, and riparian areas. Cherry plum’s yellow to dark red fruits are distributed widely by people, birds, raccoons, and other wildlife. […]