E-Flora BC: Electronic Atlas of the Flora of British Columbia

Senecio triangularis Hook.
arrow-leaved groundsel (arrowleaf ragwort; arrow-leaved ragwort)
Asteraceae (Aster family)

Introduction to Vascular Plants

© Jim Riley  Email the photographer   (Photo ID #28872)

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Distribution of Senecio triangularis
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Species Information

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Perennial herb from a fibrous-rooted, woody stem-base or rhizome; stems erect, solitary or few, branched above, glabrous to sparsely short-hairy above, 0.2-1.5 m tall.
Basal leaves triangular to heart-shaped, squared-off at the base; strongly toothed, stalked, 2.5-10 cm long including the stalks, 0.4-4.5 cm wide, hairless except for short hairs on the veins beneath, sometimes deciduous by flowering time; stem leaves similar, larger, 2.5-25 cm long, 0.4-8.5 cm wide, gradually reduced upwards, becoming unstalked.
Heads with ray and disk flowers, few to more often numerous on sparsely hairy stalks in a short, flat-topped inflorescence; involucres 7-12 mm tall; involucral bracts lanceolate, conspicuously black-tipped, sometimes also sparsely hairy or rarely with inconspicuous unstalked glands at the tips; bracteoles conspicuous, black-tipped, hairy; ray fowers yellow, mostly 7-14 mm long; disk flowers yellow.
Achenes oblong, faintly ribbed, glabrous; pappus of white hairlike bristles.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Blooming Period:
Mid Summer
Fruit/Seed characteristics:
Colour: Brown
Present over the Fall
Source:  The USDA

Habitat / Range

Moist to mesic meadows, streambanks, avalanche tracks and forest openings from the lowland to lower alpine zones; common throughout BC; N to S AK, S YT and SW NT, E to SK and S to NM and CA.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Senecio triangularis

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres) 3 1568 2640
Slope Gradient (%) 0 16 420
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
0 160 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
0 5 8
Modal Nutrient Regime
Number of field plots
 species was recorded in:
Modal BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in: AT(72), BAFA(108), BWBS(15), CMA(6), CWH(31), ESSF(2363), ICH(201), IDF(18), IMA(35), MH(69), MS(202), SBPS(2), SBS(237), SWB(88)

Ecological Indicator Information

A shade-tolerant to very shade-intolerant, montane to alpine, Western North American forb distributed equally in the Pacific and Cordilleran regions. Occurs on very moist to wet, nitrogen-rich soils within alpine tundra, boreal. cool temperate, and cool mesothermal climates; its occurrence increases with precipitation. Scattered to plentiful in meadow­like communities and the herbaceous understory of open-canopy forests on water-receiving and water-collecting sites. A nitrophytic species characteristic of Moder and Mull humus forms.

SourceIndicator Plants of Coastal British Columbia (Information applies to coastal locations only)


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is not evaluated, unknown or variable.

Synonyms and Alternate Names

Senecio gibbsonsii Greene
Senecio triangularis var. angustifolius G.N. Jones

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References