Senecio hydrophiloides
Sweet marsh ragwort
(c) Steve Matson, some rights reserved (CC BY), uploaded by Steve Matson · licence
Family: Asteraceae · Type: Herb · Native
Conservation status: CNPS 4.2
Senecio hydrophiloides (Sweet marsh ragwort) is a native California herb in the Asteraceae family, recognized by moist habitat preference, tall stature, typically discoid heads.
Sweet marsh ragwort is a California native perennial ranked 4.2 by CNPS, found in northern Sierra Nevada Mountains, Modoc Plateau, and high Cascade Range habitats on damp hillsides, meadows, and seeps at elevations of 1,200 to 2,200 meters. Flowering from June to August, this plant produces yellow disk flowers in dense, flat-topped clusters approximately 15 to 30 millimeters wide. Growing 3 to 10 feet tall with single or clustered stems that are slightly red-tinged and glabrous or minimally hairy, it emerges from an erect button-like caudex with fleshy-fibrous roots. Its leaves are firm and elliptic to broadly lanceolate, gradually reduced along the stem, measuring 5 to 15 centimeters long and 2 to 7 centimeters wide, with dentate margins and tapered bases leading to winged petioles. The fruit is small, approximately 2 to 3 millimeters long and glabrous.
Identification and appearance
Key characters: 19 sympatric species; key features are moist habitat preference, tall stature, typically discoid heads
Habitat and range
Habitat: Damp hillsides, meadows, seeps
Elevation: 1200-2200 m
Outside California: to Washington, Montana, Utah
Bloom period
Senecio hydrophiloides blooms Jun-Aug.
Conservation status
CNPS 4.2
How to tell it apart
vs Packera: Senecio has larger leaves (over 2.5 inches) and often black-tipped bracts; Packera has tiny leaves (under 1.5 inches) with green or reddish tips.; vs Sonchus: Senecio has yellow daisy flowers with a neat single row of bracts; Sonchus has dandelion-like flowers and milky sap when broken.; vs Dudleya: Senecio is in the sunflower family with daisy flowers; Dudleya is a succulent with thick fleshy leaves and star-shaped flowers.; vs Ericameria: Senecio has one main row of equal bracts around flower heads; Ericameria has 2-4 overlapping rows of unequal bracts.; vs Taraxacum: Senecio has branching stems with multiple flower heads; Taraxacum has leafless hollow stems with single dandelion-like heads.
Frequently asked questions
Is Senecio hydrophiloides native to California?
Yes. Senecio hydrophiloides is native to California (recorded as native).
When does Senecio hydrophiloides bloom?
Senecio hydrophiloides blooms Jun-Aug.
What plant family does Senecio hydrophiloides belong to?
Senecio hydrophiloides is in the Asteraceae family, genus Senecio.
Is Senecio hydrophiloides rare or endangered?
Senecio hydrophiloides carries California Rare Plant Rank 4.2, state rank S4.
What habitat does Senecio hydrophiloides grow in?
Senecio hydrophiloides grows in Damp hillsides, meadows, seeps.
Related species
Other California species in the same genus, family, or bioregion.
- Senecio hydrophilus — Water ragwort
- Senecio integerrimus — Lambstongue ragwort
- Senecio integerrimus var. exaltatus — Columbia ragwort
- Senecio integerrimus var. major — Lambs-tongue ragwort
- Senecio integerrimus var. ochroleucus — Pale-yellow ragwort
- Senecio linearifolius var. linearifolius — Linear-leaved australian fireweed
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · 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.