Helenium amarum var. amarum
Yellowdicks
(c) Dan Vickers, some rights reserved (CC BY), uploaded by Dan Vickers · licence
Family: Asteraceae · Type: Herb · Not Native
Helenium amarum var. amarum (Yellowdicks) is a non-native California herb in the Asteraceae family, recognized by . Key features: non-native status, small size, annual habit.
Yellowdicks is a naturalized annual found in the San Joaquin Valley and San Francisco Bay Area bioregions in disturbed areas and fields at elevations of 20 to 400 meters. Flowering from July to October, this plant produces yellow flowers in heads 5 to 9 millimeters long, with 8 to 10 ray flowers and 75 to 150 disk flowers. Growing 20 to 60 centimeters tall with multiple branching stems that are glabrous or sparsely hairy, it develops numerous flower heads across disturbed landscapes. Its leaves are primarily linear, with basal leaves that may be entire or pinnately toothed and cauline leaves typically narrow and entire. The fruit is small, approximately 1 to 1.3 millimeters long, with 6 to 8 pappus scales that have awn-like tips.
Identification and appearance
Key characters: 2 sympatric species. Key features: non-native status, small size, annual habit
Habitat and range
Habitat: Disturbed areas, fields
Elevation: 20-400 m
Outside California: native to southeastern United States
Bloom period
Helenium amarum var. amarum blooms Jul-Oct.
How to tell it apart
vs Rudbeckia: Rudbeckia has a dark purple-brown cone; Helenium has a yellow or greenish spherical disk.; vs Cotula: Cotula lacks ray flowers entirely; Helenium has yellow rays around the spherical disk.; vs Hymenoxys: Hymenoxys has deeply dissected ferny leaves; Helenium leaves are entire or shallowly lobed.; vs Oncosiphon: Oncosiphon lacks ray flowers and has finely divided ferny leaves; Helenium has rays and simple to lobed leaves.; vs Helianthella: Helianthella has flat disks with erect phyllaries; Helenium has spherical disks with reflexed phyllaries.
Frequently asked questions
Is Helenium amarum var. amarum native to California?
No. Helenium amarum var. amarum is not native to California (recorded as not native).
When does Helenium amarum var. amarum bloom?
Helenium amarum var. amarum blooms Jul-Oct.
What plant family does Helenium amarum var. amarum belong to?
Helenium amarum var. amarum is in the Asteraceae family, genus Helenium.
What habitat does Helenium amarum var. amarum grow in?
Helenium amarum var. amarum grows in Disturbed areas, fields.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · 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.