Arctotheca prostrata (sterile capeweed) is a rosette-forming plant (family Asteraceae) found in coastal prairies and as an urban escape in the San Francisco Bay area and California’s north, central and southern coast. The infertile type of capeweed is cultivated for use as an ornamental groundcover, and a fertile type has also been introduced. The infertile […]

Arctotheca calendula (fertile capeweed) is a rosette-forming plant (family Asteraceae) found in coastal prairies of the San Francisco Bay area and California’s north coast. An infertile type of capeweed is cultivated for use as an ornamental groundcover, and a fertile type has also been introduced. The infertile type is very competitive and can escape cultivation locally […]

Bromus madritensis ssp. rubens (=B. rubens) (red brome) is a cool-season annual grass (family Poaceae) found throughout California, especially in the southern part of the state. Red brome invades disturbed areas, roadsides, agricultural fields, rangelands, and forestry sites, in addition to native communities. Red brome is spreading rapidly in desert shrublands, pinyon pine-juniper communities, three-needle pine woodlands, and […]

Centaurea jacea ssp. pratensis (=Centaurea debeauxii or C. jacea x C. nigra or C. x pratensis) (meadow knapweed) is a bushy perennial (family Asteraceae) found in a small number of disturbed areas in Siskiyou, Del Norte, and Humboldt Counties in northwestern California. Meadow knapweed reproduces by seed and via shoots from the parent plant, and is known […]

Fallopia japonica (=Polygonum cuspidatum) (Japanese 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. […]

Festuca perennis (Italian ryegrass) is an annual or biennial grass (family Poaceae) found throughout California except in the Great Basin and deserts. Plants can be distinguished from other several other common grasses by having an unbranched inflorescence with florets and seed that have no awns. Spikelets are arranged in an alternating pattern on stem and […]

Hedera helix (English ivy) is a perennial evergreen woody vine (family Araliaceae). It is found throughout California along the coast, as well as in Shasta and Butte Counties. English ivy grows vigorously in forests where nothing else seems able to compete and inhibits regeneration of understory plants, including forest wildflowers and new trees and shrubs. […]

Hedera canariensis (Algerian ivy) is a perennial woody vine (family Araliaceae) that is native to the Canary Islands and the Mediterranean coast of North Africa. It is found throughout California along the coast, and is less widespread than its close relative English ivy. Algerian ivy grows vigorously in forests where nothing else seems able to […]

Hordeum murinum (hare barley or foxtail) is an annual grass (family Poaceae) that is native to the Mediterranean, northern Africa, and temperate Asia. It is characterized by having a low stature (<=10 cm), inflorescences with long awns, and spikelets (each containing three florets) that disarticulate when they mature. Hare barely is common throughout California in […]

Lepidium chalepense (lens-podded whitetop) is a perennial (family Brassicaceae) that is relatively infrequent in California. Lepidium draba (hoary cress) and L. chalepense grow in the many habitats and areas of the state, except in the Mojave and Colorado deserts. However, L. draba occurs in wet and dry grasslands, scrubs, and arid areas with alkali soils and […]