Layia septentrionalis
Colusa layia
(c) Trevor Van Loon, some rights reserved (CC BY) · licence
Family: Asteraceae · Type: Herb · Native
Conservation status: CNPS 1B.2
Layia septentrionalis (Colusa layia) is a native California herb in the Asteraceae family, recognized by long disk corollas and densely plumose, adaxially woolly pappus.
Colusa layia is a rare (CNPS 1B.2) California native annual found in central North Coast Ranges Interior and the Sutter Buttes in serpentine or sandy soils at elevations of 100 to 900 meters. Flowering from April to June, this plant produces yellow ray flowers 4 to 15 millimeters long with bright yellow disk flowers arranged in ellipsoid to bell-shaped heads. Growing 6 to 35 centimeters tall with purple-streaked stems that are glandular and not strongly scented, it develops a delicate, branching form. Its leaves range from 4 to 70 millimeters long, linear to lanceolate, with proximal leaves often deeply lobed nearly to the midvein. The fruit features ray fruits that are glabrous or sparsely hairy, with a distinctive pappus of 16 to 22 white, plumose bristles.
Identification and appearance
Key characters: 3 sympatric species; long disk corollas and densely plumose, adaxially woolly pappus
Habitat and range
Habitat: Serpentine or sandy soils
Elevation: 100-900 m
Outside California: southwestern Oregon
Bloom period
Layia septentrionalis blooms Apr-Jun.
Conservation status
CNPS 1B.2
How to tell it apart
vs Madia: Layia has prominent feathery seed bristles 2-4mm; Madia has tiny or no seed bristles.; vs Glebionis: Layia has feathery white seed plumes; Glebionis has yellow-orange rays and no seed plumes.; vs Deinandra: Layia has fluffy feathery seed bristles; Deinandra has straight, non-feathery bristles.; vs Monoptilon: Layia has 2-4mm feathery bristles; Monoptilon has shorter non-feathery bristles.; vs Hemizonia: Layia has prominent feathery seed plumes; Hemizonia has short non-feathery bristles or scales.
Frequently asked questions
Is Layia septentrionalis native to California?
Yes. Layia septentrionalis is native to California (recorded as native).
When does Layia septentrionalis bloom?
Layia septentrionalis blooms Apr-Jun.
What plant family does Layia septentrionalis belong to?
Layia septentrionalis is in the Asteraceae family, genus Layia.
Is Layia septentrionalis rare or endangered?
Layia septentrionalis carries California Rare Plant Rank 1B.2, state rank S2.
What habitat does Layia septentrionalis grow in?
Layia septentrionalis grows in Serpentine or sandy soils.
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.