Dittrichia viscosa
False yellowhead, False Yellowhead
(c) Gianni Del Bufalo bygdb, some rights reserved (CC BY), uploaded by Gianni Del Bufalo bygdb · licence
Family: Asteraceae · Type: Subshrub · Not Native
Conservation status: Cal-IPC Yes
Dittrichia viscosa (False yellowhead) is a non-native California subshrub in the Asteraceae family, recognized by woody-stemmed annual 4-13 dm tall with broader lanceolate leaves.
False yellowhead is a naturalized annual found in the central Coast and southwest Santa Clara Valley regions along roadsides, disturbed places, and creeksides at elevations around 43 meters. Flowering from September to November, this plant produces yellow flowers in heads with 12 to 18 ray flowers and 25 to 40 disk flowers. Growing 4 to 13 decimeters tall with multiple branched, woody stems emerging near the base, it develops an erect, multi-stemmed structure. Its cauline leaves are lanceolate to oblanceolate, 4 to 6 centimeters long and 6 to 13 millimeters wide, with scattered teeth on lower leaves and nearly smooth edges on upper leaves. The fruit is approximately 2 millimeters long with 15 to 20 pappus bristles measuring 4 to 6 millimeters.
Identification and appearance
Key characters: 0 sympatric species - geographically isolated; woody-stemmed annual 4-13 dm tall with broader lanceolate leaves
Habitat and range
Habitat: roadsides, disturbed places, creeksides
Elevation: +- 43 m.
Outside California: native to Mediterranean Basin
Bloom period
Dittrichia viscosa blooms Sep-Nov.
Conservation status
Cal-IPC Yes
How to tell it apart
vs Solidago: Dittrichia is intensely sticky-glandular and camphor-scented, a bushy plant with small spreading heads; goldenrods are non-sticky, scentless, with heads massed in dense one-sided plume-like sprays.; vs Grindelia: Dittrichia has narrow, few-toothed leaves and small heads with short rays; Grindelia (gumweed) has broad clasping toothed leaves and large heads with a gummy white-exuding involucre and hooked phyllaries.; vs Baccharis: Dittrichia has short yellow ray flowers and glandular, ill-smelling foliage; Baccharis is dioecious with rayless heads and no glandular stink.; vs Erigeron: Dittrichia has distinct short yellow rays and sticky aromatic herbage; horseweed-type Erigeron/Conyza has minute, barely visible rays and is not sticky.; vs Pulicaria: Dittrichia is strongly resinous-sticky with a woody base and a foul smell; Pulicaria (false fleabane) is softer, less glandular and not woody-based.
Frequently asked questions
Is Dittrichia viscosa native to California?
No. Dittrichia viscosa is not native to California (recorded as not native).
When does Dittrichia viscosa bloom?
Dittrichia viscosa blooms Sep-Nov.
What plant family does Dittrichia viscosa belong to?
Dittrichia viscosa is in the Asteraceae family, genus Dittrichia.
Is Dittrichia viscosa invasive in California?
Dittrichia viscosa is listed by Cal-IPC with an invasiveness rating of Yes.
What habitat does Dittrichia viscosa grow in?
Dittrichia viscosa grows in roadsides, disturbed places, creeksides.
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.