Senecio triangularis
Arrowleaf ragwort
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Family: Asteraceae · Type: Subshrub · Native
Senecio triangularis (Arrowleaf ragwort) is a native California subshrub in the Asteraceae family, recognized by unique triangular leaf shape diagnostic.
Arrowleaf ragwort is a California native perennial found in the Klamath Ranges, Cascade Range, Sierra Nevada, southern California mountains, and Great Basin in damp places, open conifer woodland, and rocky streambanks at elevations of 100 to 3,300 meters. Flowering from June to September, this plant produces yellow ray flowers 9 to 15 millimeters long with yellow disk flowers in heads arranged in flat-topped or raceme-like clusters. Growing 50 to 120 centimeters tall with 1 to several stems emerging from a branched woody base, it has glabrous or sparsely hairy stems. Its leaves are broadly triangular, 3 to 10 centimeters long and 2 to 6 centimeters wide, with dentate edges and varying from narrowly to widely triangular, tapering to a truncate or heart-shaped base. The fruit is 2.5 to 3.5 millimeters long and glabrous.
Identification and appearance
Key characters: 23 sympatric species; unique triangular leaf shape diagnostic
Habitat and range
Habitat: Damp places, open conifer woodland, rocky streambanks
Elevation: 100-3300 m
Outside California: to Alaska, Wyoming, New Mexico
Bloom period
Senecio triangularis blooms Jun-Sep.
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 triangularis native to California?
Yes. Senecio triangularis is native to California (recorded as native).
When does Senecio triangularis bloom?
Senecio triangularis blooms Jun-Sep.
What plant family does Senecio triangularis belong to?
Senecio triangularis is in the Asteraceae family, genus Senecio.
What habitat does Senecio triangularis grow in?
Senecio triangularis grows in Damp places, open conifer woodland, rocky streambanks.
Related species
Other California species in the same genus, family, or bioregion.
- Senecio vulgaris — Common groundsel
- Senecio angustifolius — Narrow-leaved south african ragwort
- Senecio aphanactis — Chaparral ragwort
- Senecio aronicoides — Rayless ragwort
- Senecio astephanus — San gabriel ragwort
- Senecio blochmaniae — Blochman's ragwort
- Sericocarpus oregonensis — Oregon whitetop aster
- Sericocarpus oregonensis subsp. californicus
- Sericocarpus oregonensis subsp. oregonensis
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.