Lythrum californicum
California loosestrife
Photo by Chez Brungraber
Family: Lythraceae · Type: Subshrub · Native
Lythrum californicum (California loosestrife) is a native California subshrub in the Lythraceae family, recognized by size, gray-glaucous appearance, and flower arrangement.
California loosestrife is a native perennial herb found in southern North Coast Ranges Interior, Sierra Nevada Foothills, southern Sierra Nevada, Central Valley, Central Western California, Southwest California, White and Inyo Mountains, and Desert regions in marshes and pond and stream margins at elevations below 2,200 meters. Flowering from April to September, this plant produces purple flowers 4 to 8 millimeters long with distinctive heterostylous forms. Growing 20 to 60 centimeters tall with many branching stems that are gray-glaucous and erect, it develops a robust and spreading growth habit. Its leaves range from 1 to 7 centimeters long, with lower leaves opposite and linear, and upper leaves alternate and lance-linear, displaying a subtle gray-green coloration. The plant has a unique floral structure with two style forms and 6 stamens, creating intricate pollination possibilities in wetland habitats.
Identification and appearance
Key characters: 4 sympatric species; distinguished by size, gray-glaucous appearance, and flower arrangement
Habitat and range
Habitat: Marshes, pond and stream margins
Elevation: < 2200 m
California counties: San Bernardino, Los Angeles, San Diego, Kern, Ventura, Riverside, Orange, Siskiyou, Inyo, Tulare, San Mateo, Santa Barbara, Marin, Monterey, Yolo, Fresno, Amador, Alameda, Colusa, Santa Clara, Solano, Contra Costa, San Luis Obispo, Imperial, San Francisco, Stanislaus, San Joaquin, Calaveras, Mendocino, Glenn, Butte, Sutter, Tehama, Madera, Merced, Sacramento, Napa, Tuolumne, Lake, Mono
Outside California: to central United States, northern Mexico
Bloom period
Lythrum californicum blooms Apr-Sep.
How to tell it apart
vs Coleonema: Lythrum has tubular flower bases and wetland habitat; Coleonema has open flowers and grows in dry upland areas.; vs Cuphea: Lythrum has symmetrical cylindrical flower tubes; Cuphea has asymmetrical, curved tubular flowers.; vs Epilobium: Lythrum has cylindrical flower tubes with leaves in pairs/whorls; Epilobium has cross-shaped flowers with inferior ovaries.; vs Salvia: Lythrum has cylindrical flower tubes and smooth leaf margins; Salvia has hooded, 2-lipped flowers and square stems.; vs Lysimachia: Lythrum has distinct tubular flower bases; Lysimachia has flat, wheel-shaped flowers without tubes.
Frequently asked questions
Is Lythrum californicum native to California?
Yes. Lythrum californicum is native to California (recorded as native).
When does Lythrum californicum bloom?
Lythrum californicum blooms Apr-Sep.
Where in California does Lythrum californicum grow?
Lythrum californicum occurs in San Bernardino, Los Angeles, San Diego, Kern, Ventura, Riverside, Orange, Siskiyou and other counties, at elevations of < 2200 m.
What plant family does Lythrum californicum belong to?
Lythrum californicum is in the Lythraceae family, genus Lythrum.
What habitat does Lythrum californicum grow in?
Lythrum californicum grows in Marshes, pond and stream margins.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.