Rytidosperma caespitosum (tufted wallabygrass) is a perennial grass (family Poaceae) that is native to Australia and is found to date in the San Francisco Bay area and San Diego County. Plant grow to nearly 1m as small bunch grasses; leaves and leaf sheathes are very hairy, with hairs erect, especially at leaf blade/sheath axil. Inflorescences […]

Salpichroa origanifolia (lily of the valley vine) is a vine (family Solanaceae) with white flowers and oval-shaped leaves found in the San Francisco Bay area, Sacramento Valley and southwestern ranges of California. It is native to South America. It occurs in grasslands. It spreads via seeds, root fragments and pieces of underground stems. These stems […]

Salsola ryanii (Ryan’s Russian thistle) is an annual herb/ (family Chenopodiaceae) with white to pink papery flowers and small narrow leaves found in the Central Valley and southwestern ranges of California. It is native to Australia or South Africa. It favors grasslands and dunes. It spreads via seed. It exhibits a “tumbling” habit allowing long-distance […]

Scabiosa atropurpurea (pincushion flower) is a herb/ (family Dipsacaceae) with red to purple flowers and narrow leaves found in the Central Valley and central and south coast ranges of California. It is native to southern Europe. It favors grasslands. It propagates by seeds which are dispersed by animals.

Scolymus hispanicus (goldenthistle) is a herb/ (family Asteraceae) with yellow flowers and spiny narrow leaves found in the central western ranges of California. It is native to Europe. It grows in grasslands. It propagates by seed. The spiny seed heads can get caught in wool, carried by wind and spread by agricultural equipment.

Senecio linearifolius (fireweed groundsel) is a herb/subshrub (family Asteraceae) with yellow flowers and narrow leaves found in the south coast ranges of California. It is native to Australia. It favors grasslands and dunes. It spreads via seeds which travel by wind.

Solanum aviculare (New Zealand nightshade) is a subshrub/shrub (family Solanaceae) with purple flowers and narrow leaves found in the coastal ranges and desert ranges of California. It is native to Australia. It favors forests and grasslands. It propagates by seeds which are dispersed via birds.

Solanum carolinense (Carolina horsenettle) is a perennial herb/ (family Solanaceae) with white to purple flowers and lobed leaves found in the Sierra Nevada range, Central Valley, south coast ranges and northern ranges of California. It is native to the central and eastern United States and northern Mexico. It favors grasslands and dunes. It spreads via […]

Sphaerophysa salsula (alkali swainsonpea) is a perennial herb/ (family Fabaceae) with red flowers and small oval-shaped leaves found in the San Joaquin Valley in California. It is native to Asia. It favors grasslands. It spreads via water and contaminated alfalfa seed.

Stipa brachychaeta (punagrass) is a perennial grass (family Poaceae) that can grow to be more than 2 feet tall and is found in the Central Valley and the central and south coast ranges of California. It is native to South America. It favors grasslands, woodlands, and riparian and bottomland habitat. It spreads via seed and […]