Desmazeria rigida
Ferngrass
(c) Benjamin Lavin, some rights reserved (CC BY) · licence
Family: Poaceae · Type: Grass · Not Native
Desmazeria rigida (Ferngrass) is a non-native California grass in the Poaceae family, recognized by European introduction with distinctive rigid branching pattern unique among California grasses.
Ferngrass is a naturalized annual grass found in southern California coastal regions including Santa Catalina Island, southern Coast Ranges, and San Francisco Bay Area in open, often sandy sites at elevations below 700 meters. Flowering from April to September, this plant produces pale translucent spikelets with delicate, narrow inflorescences 4 to 8 centimeters long. Growing with generally erect stems 10 to 60 centimeters tall, it has smooth, glabrous green stems that spread widely. Its narrow leaf blades are flat, measuring 2 to 25 centimeters long and just 1 to 3 millimeters wide, with a fine, delicate texture. The spikelets feature 5 to 12 florets with translucent tips that appear acute or softly pointed.
Identification and appearance
Key characters: European introduction with distinctive rigid branching pattern unique among California grasses
Habitat and range
Habitat: Open, often sandy sites
Elevation: < 700 m
California counties: Santa Barbara, San Diego, Los Angeles, San Bernardino, Marin, Monterey, San Mateo, Alameda, Sacramento, Butte, Santa Clara, Santa Cruz, San Luis Obispo, Sonoma, San Francisco
Outside California: North America, native to southern and western Europe
Bloom period
Desmazeria rigida blooms Apr-Sep.
How to tell it apart
vs Hordeum: Desmazeria has a thickened axis that breaks apart; Hordeum has three spikelets per node.; vs Hilaria: Desmazeria has a segmented, breaking axis; Hilaria has three-spikelet clusters on solid stems.; vs Bromus: Desmazeria has rounded seed husks; Bromus has flattened seed husks and closed leaf sheaths.; vs Festuca: Desmazeria axis breaks into segments with seeds; Festuca seeds drop individually from intact stalks.; vs Brachypodium: Desmazeria axis segments fall with seeds; Brachypodium seeds drop from persistent stalks.
Frequently asked questions
Is Desmazeria rigida native to California?
No. Desmazeria rigida is not native to California (recorded as not native).
When does Desmazeria rigida bloom?
Desmazeria rigida blooms Apr-Sep.
Where in California does Desmazeria rigida grow?
Desmazeria rigida occurs in Santa Barbara, San Diego, Los Angeles, San Bernardino, Marin, Monterey, San Mateo, Alameda and other counties, at elevations of < 700 m.
What plant family does Desmazeria rigida belong to?
Desmazeria rigida is in the Poaceae family, genus Desmazeria.
What habitat does Desmazeria rigida grow in?
Desmazeria rigida grows in Open, often sandy sites.
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.