Parthenium hysterophorus (Santa Maria feverfew) is a herb (family Asteraceae) with white flowers and lobed leaves found in the south coast ranges of California. It is native to the American tropics. It favors grasslands and riparian and bottomland habitat. It is a prolific seed producer. Its seeds travel via wind, water, birds, vehicles, farm machinery […]

Paspalum urvillei (Vasey’s grass) is a perennial grass (family Poaceae) that can grow up to 6 feet tall found in the Central Valley and central and south coast ranges of California. It is native to South America. It favors grasslands and riparian and bottomland habitat. It spreads by seed and by rhizome. The seeds are […]

Paspalum vaginatum (seashore Paspalum) is a perennial grass (family Poaceae) that can grow to approximately 20 inches tall and is found in the Sonoran Desert and south coast ranges of California. It is native to southeastern North America, other parts of tropical Central and South America and Africa. It favors dunes and bog and marsh […]

Passiflora tarminiana (banana passionfruit) is a vine (family Passifloraceae) with pink flowers and lobed leaves found in the central coast ranges of California. It is native to South America. It favors woodlands, grasslands, scrub and chaparral, forests, and riparian and bottomland habitat. It spreads via seeds and detached stems that re-root. Seeds from the large, […]

Peganum harmala (African-rue) is a perennial herb/ (family Zygophyllaceae) with white flowers and thin narrow leaves found in the Mojave Desert in California. It is native to the Mediterranean and central Asia. It favors grasslands. It spreads via seeds and roots. Seeds are dispersed by water, animals, farm machinery and other vehicles. Local spread occurs […]

Pennisetum villosum (feathertop) is a perennial grass (family Poaceae) with fuzzy white to light brown flowers and long narrow leaves found in the Sierra Nevada range, central coast ranges and southwestern ranges of California. It is native to Africa. It favors grasslands, dunes, and scrub and chaparral habitat. It spreads via rhizomes and seed. Seeds […]

Persicaria wallichii (Himalayan knotweed) is a perennial herb/ (family Polygonaceae) with white flowers and narrow leaves found in the north and central coast ranges of California. It is native to south-central Asia. It favors grasslands, wetlands, bog and marsh, and riparian and bottomland habitat. It spreads via small fragments that form new plants. Means of […]

Pittosporum undulatum (Victorian box) is a shrub/tree (family Pittosporaceae) with white flowers and narrow wavy leaves found in the San Francisco Bay area, Channel Islands and coastal ranges of California. It is native to southeastern Australia. It favors forests, woodlands, grasslands, and scrub and chaparral habitat. It spreads via seeds and roots. The sticky seeds […]

Plecostachys serpyllifolia (petite-licorice) is a subshrub/shrub (family Asteraceae) with tiny white flowers and tiny oval-shaped leaves found in the coastal ranges of California. It is native to southern Africa. It favors grasslands and meadows. It reproduces via seeds which travel by wind.

Polygala myrtifolia (myrtle-leaf milkwort) is a shrub (family Polygalaceae) with pink-purple flowers and narrow leaves found in the central coast ranges of California. It is native to South Africa. It favors grasslands, woodlands, and riparian and bottomland habitat. It spreads only by seeds which travel via water, birds, ants and dumped garden waste.