Androsace filiformis
Slender-stemmed androsace, slender-stemmed androsace, slender-stemmed androsace
(c) Екатерина Гущина, some rights reserved (CC BY) · licence
Family: Primulaceae · Type: Herb · Native
Conservation status: CNPS 2B.3
Androsace filiformis (Slender-stemmed androsace) is a native California herb in the Primulaceae family, recognized by leaf shape, flower proportions, and specific habitat.
Slender-stemmed androsace is a rare (CNPS 2B.3) California native annual found in the southern slope of Willow Creek Mountain in northern Siskiyou County in mountain meadows at an elevation of 1,800 meters. Flowering from May to June, this plant produces delicate white flowers with small corolla tubes that extend beyond the calyx. Growing with thin stems 3 to 12 centimeters tall, it has a glabrous or slightly glandular-hairy structure. Its leaves are small, 3 to 20 millimeters long, ovate to triangular in shape, with fine teeth near the leaf tip and abruptly narrowed to a slender petiole. The plant's multiple peduncles bear small involucre bracts less than 0.5 millimeters wide, creating a delicate, sparse inflorescence.
Identification and appearance
Key characters: 1 sympatric species; distinguished by leaf shape, flower proportions, and specific habitat
Habitat and range
Habitat: Meadows
Elevation: 1800 m
Outside California: sporadic to Washington, Rocky Mountains, also in Eurasia
Bloom period
Androsace filiformis blooms May?-Jun.
Conservation status
CNPS 2B.3
How to tell it apart
vs Pelargonium: Androsace has tiny white flowers (petals 1-3mm) in umbels; Pelargonium has much larger showy flowers in various colors.; vs Primula: Androsace petals face upward (1-3mm long); Primula petals reflex dramatically backward (much larger).
Frequently asked questions
Is Androsace filiformis native to California?
Yes. Androsace filiformis is native to California (recorded as native).
When does Androsace filiformis bloom?
Androsace filiformis blooms May?-Jun.
What plant family does Androsace filiformis belong to?
Androsace filiformis is in the Primulaceae family, genus Androsace.
Is Androsace filiformis rare or endangered?
Androsace filiformis carries California Rare Plant Rank 2B.3, state rank S1.
What habitat does Androsace filiformis grow in?
Androsace filiformis grows in Meadows.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · 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.