Sagina decumbens subsp. occidentalis
Western pearlwort, Western Pearlwort
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Family: Caryophyllaceae · Type: Herb · Native
Sagina decumbens subsp. occidentalis (Western pearlwort) is a native California herb in the Caryophyllaceae family, recognized by annual habit with 5 petals equal to sepals.
Western pearlwort is a California native annual found in northwestern California, northern Sierra Nevada, Central Valley, Central Coast, San Francisco Bay Area, southern California coastal areas, Channel Islands, Peninsular Ranges, and Modoc Plateau in dry streams, chaparral, grassy areas, rock outcrops, and vernal pools at elevations below 2,000 meters. Flowering from spring to early summer, this delicate plant produces small white flowers with five petals approximately equal in length to its sepals. Growing with thread-like stems 4 to 16 centimeters tall, generally erect or ascending and glabrous or slightly glandular-hairy toward the tips, it forms a slender and delicate structure. Its leaves are narrowly linear, 4 to 20 millimeters long, and glabrous, creating a fine, sparse appearance. The tiny brown seeds are less than half a millimeter long with a grooved back, contributing to its subtle and intricate botanical character.
Identification and appearance
Key characters: 4 sympatric species; key features are annual habit with 5 petals equal to sepals
Habitat and range
Habitat: dry streams, chaparral, grassy areas, rock outcrops, vernal pools
Elevation: < 2000 m
California counties: Los Angeles, San Diego, Del Norte, Alameda, Humboldt, Kern, Marin, Modoc, Monterey, Riverside, Santa Barbara, Santa Cruz, Siskiyou, Sonoma, Stanislaus, Tulare, Butte, San Bernardino, Orange, San Mateo, Sacramento, Madera, Mendocino, Tehama, Glenn, Colusa, Plumas, Merced, Solano, Calaveras, Santa Clara, Napa, Shasta, Sierra, Contra Costa, San Francisco, San Luis Obispo, El Dorado, Trinity, Ventura, Mariposa, Yolo
Outside California: to British Columbia, Baja California
Bloom period
Sagina decumbens subsp. occidentalis blooms Spring-early summer.
How to tell it apart
vs Erigeron: Sagina forms moss-like mats with thread leaves; Erigeron has narrow but broader leaves and daisy-like flowers.; vs Sabulina: Sagina has extremely thread-like leaves forming dense mats; Sabulina has slightly wider, less moss-like leaves.; vs Soliva: Sagina forms green moss-like mats with tiny white flowers; Soliva forms flattened rosettes with no petals.; vs Spergula: Sagina has thread-like leaves in pairs; Spergula has leaves in whorls around the stem.; vs Holosteum: Sagina has tiny scattered flowers in loose clusters; Holosteum has umbrella-shaped flower clusters.
Frequently asked questions
Is Sagina decumbens subsp. occidentalis native to California?
Yes. Sagina decumbens subsp. occidentalis is native to California (recorded as native).
When does Sagina decumbens subsp. occidentalis bloom?
Sagina decumbens subsp. occidentalis blooms Spring-early summer.
Where in California does Sagina decumbens subsp. occidentalis grow?
Sagina decumbens subsp. occidentalis occurs in Los Angeles, San Diego, Del Norte, Alameda, Humboldt, Kern, Marin, Modoc and other counties, at elevations of < 2000 m.
What plant family does Sagina decumbens subsp. occidentalis belong to?
Sagina decumbens subsp. occidentalis is in the Caryophyllaceae family, genus Sagina.
What habitat does Sagina decumbens subsp. occidentalis grow in?
Sagina decumbens subsp. occidentalis grows in dry streams, chaparral, grassy areas, rock outcrops, vernal pools.
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.