Holosteum umbellatum subsp. umbellatum
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Family: Caryophyllaceae · Type: Annual · Not Native
Holosteum umbellatum subsp. umbellatum is a non-native California annual in the Caryophyllaceae family, recognized by Only Holosteum species in North America; European genus with limited naturalization.
Holosteum is a naturalized annual found in the Klamath Ranges, Cascade Range, and central Coast Ranges in disturbed areas and roadsides at elevations below 1,270 meters. Flowering from late winter to early spring, this plant produces delicate white petals that are narrowly elliptic in shape. Growing with slender stems 5 to 25 centimeters tall, it features glandular hairs concentrated near the middle of the stem. Its cauline leaves occur in 1 to 4 pairs in the lower half of the plant, with blades 2 to 30 millimeters long that are either glabrous or have glandular hairs along the margins. Small seeds are compressed with a marginal ridge and low, rounded tubercles.
Identification and appearance
Key characters: Only Holosteum species in North America; European genus with limited naturalization
Habitat and range
Habitat: Uncommon. Disturbed areas, roadsides
Elevation: < 1270 m
Outside California: to British Columbia, eastern North America, native to Europe, central and southwestern Asia, northern Africa
Bloom period
Holosteum umbellatum subsp. umbellatum blooms Late winter-early spring.
How to tell it apart
vs Sagina: Holosteum has umbrella-like flower clusters with jagged petals; Sagina has scattered tiny flowers with smooth or no petals.; vs Eremogone: Holosteum has broad leaves and jagged petals in umbels; Eremogone forms needle-leaved cushions.; vs Arenaria: Holosteum flowers cluster in tight umbels with ragged petals; Arenaria flowers scatter along stems with smooth petals.; vs Moehringia: Holosteum has umbrella flower clusters and jagged petals; Moehringia has scattered flowers and smooth petals.; vs Minuartia: Holosteum has umbrella-shaped flower clusters; Minuartia has flowers scattered along branching stems.
Frequently asked questions
Is Holosteum umbellatum subsp. umbellatum native to California?
No. Holosteum umbellatum subsp. umbellatum is not native to California (recorded as not native).
When does Holosteum umbellatum subsp. umbellatum bloom?
Holosteum umbellatum subsp. umbellatum blooms Late winter-early spring.
What plant family does Holosteum umbellatum subsp. umbellatum belong to?
Holosteum umbellatum subsp. umbellatum is in the Caryophyllaceae family, genus Holosteum.
What habitat does Holosteum umbellatum subsp. umbellatum grow in?
Holosteum umbellatum subsp. umbellatum grows in Uncommon. Disturbed areas, roadsides.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CalPhotos
Last updated 2026-09-30
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.