Sorghum halepense

Johnson grass

Family: Poaceae · Type: perennial · Not Native

Johnson grass is a naturalized perennial found in northwestern California, the Sierra Nevada Foothills, Sierra Nevada, Central Valley, central western California, southwestern California, and desert regions in disturbed areas, ditch banks, and roadsides at elevations below 1,160 meters. Flowering from May to August, this plant produces pale green to whitish flowers in large, spreading panicles 5 to 25 centimeters wide. Growing with robust erect stems 50 to 200 centimeters tall, it forms dense clumps with multiple branching stems. Its long, wide leaves measure 5 to 90 centimeters in length and 0.5 to 4 centimeters across, with a distinctive ligule 2 to 6 millimeters long. The plant can spread aggressively through both seeds and rhizomes, making it a persistent invasive species in many disturbed habitats.

Habitat: Disturbed areas, ditch banks, roadsides

Bloom period: May-Aug

Elevation: < 1160 m

Bioregions: NW, CaRF, SNF, GV, CW, SW, D

California counties: Los Angeles, Orange, Alameda, Butte, Stanislaus, Tulare, Fresno, Colusa, Lake, Merced, San Luis Obispo, Nevada, Calaveras, Riverside, Glenn, San Diego, Humboldt, San Bernardino, Kings, Ventura, Imperial, Yolo, Sutter, Placer, Yuba, Sacramento, Amador, Marin, Lassen, Madera, Kern, Plumas, Santa Clara, Santa Cruz, Shasta, Solano, Trinity, Monterey, Napa, San Francisco, San Mateo, Santa Barbara, Sonoma, San Joaquin, Contra Costa, Tehama, El Dorado, Inyo, Siskiyou

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Jepson eFlora, Cal-IPC, and more.