Perideridia gairdneri subsp. gairdneri
Gairdner's yampah, Gairdner's Yampah
(c) Matt Lavin, some rights reserved (CC BY-SA) · licence
Family: Apiaceae · Type: Herb · Native
Conservation status: CNPS 4.2
Perideridia gairdneri subsp. gairdneri (Gairdner's yampah) is a native California herb in the Apiaceae family, recognized by single thick tuber diagnostic.
Gairdner's yampah is a California native perennial herb found in southern North Coast, North Coast Ranges, and southern California coastal regions in coastal flats, grassland, and pine forest at elevations below 350 meters. Flowering from June to July, this plant produces white flowers in umbels with generally 7 to 14 rays. Growing with a flexible stem and a single tuberous root 10 to 15 millimeters wide, it forms an elegant herbaceous structure. Its leaves are delicate and finely divided, typical of the carrot family, supporting its slender growth habit. The plant's single tuberous root and white flower clusters make it a distinctive component of coastal and grassland ecosystems.
Identification and appearance
Key characters: 4 sympatric species; single thick tuber diagnostic
Habitat and range
Habitat: Coastal flats, grassland, pine forest
Elevation: < 350 m
California counties: San Diego, Sonoma, San Luis Obispo, Trinity, Santa Cruz, San Mateo, Monterey, Siskiyou, Orange, Solano, Napa, Alameda, Butte, Fresno, Los Angeles, Mendocino, Plumas, Santa Clara, Sierra, Sutter, Tulare, Tuolumne, Yuba, Marin, Humboldt, Lassen, Tehama, San Benito, Modoc
Bloom period
Perideridia gairdneri subsp. gairdneri blooms Jun-Jul.
Conservation status
CNPS 4.2
How to tell it apart
vs Ligusticum: Perideridia grows from tubers in grasslands; Ligusticum grows from taproots in mountain forests.; vs Daucus: Perideridia fruits are rounded with thin ribs; Daucus fruits are bristly and form a bird's-nest cluster.; vs Eriogonum: Eriogonum is in the buckwheat family with papery flowers; Perideridia has carrot-family umbels.; vs Angelica: Perideridia has small rounded fruits; Angelica has large flattened fruits with broad wings.; vs Achillea: Achillea is in the sunflower family with flat-topped flower heads; Perideridia has carrot-family umbels.
Frequently asked questions
Is Perideridia gairdneri subsp. gairdneri native to California?
Yes. Perideridia gairdneri subsp. gairdneri is native to California (recorded as native).
When does Perideridia gairdneri subsp. gairdneri bloom?
Perideridia gairdneri subsp. gairdneri blooms Jun-Jul.
Where in California does Perideridia gairdneri subsp. gairdneri grow?
Perideridia gairdneri subsp. gairdneri occurs in San Diego, Sonoma, San Luis Obispo, Trinity, Santa Cruz, San Mateo, Monterey, Siskiyou and other counties, at elevations of < 350 m.
What plant family does Perideridia gairdneri subsp. gairdneri belong to?
Perideridia gairdneri subsp. gairdneri is in the Apiaceae family, genus Perideridia.
Is Perideridia gairdneri subsp. gairdneri rare or endangered?
Perideridia gairdneri subsp. gairdneri carries California Rare Plant Rank 4.2, state rank S3S4.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
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.