Petasites frigidus (L.) Fr.
sweet coltsfoot (arctic sweet coltsfoot)
Asteraceae (Aster family)

Introduction to Vascular Plants

Photograph

© Deborah Freeman     (Photo ID #29368)

Map

E-Flora BC Static Map

Distribution of Petasites frigidus
Click here to view the full interactive map and legend

Introduction

Four varieties of this species are presently recognized in British Columbia: var. frigidus, var.nivalis, var. palmatus, and var. sagittatus. Petasites frigidus var. sagittatus is recognized at the variety level, however, it was previously recognized at the species level in the Illustrated Flora of British Columbia. This differs from the current presentation in the Flora of North America. However, the species taxonomy will be reassessed by the BC Conservation Data Centre shortly.

The map on this species page reflects specimens in collections not identified to the sub-taxa level.

Species Information

General:
Perennial herb from a creeping root; stems erect, branched above, numerous, more or less white woolly-hairy, with parallel-veined bracts 2.5-6 cm long, reduced upwards, 5-50 cm tall, flowering stems appear before the leaves.
Leaves:
Basal leaves arising directly from the creeping root, triangular to heart-shaped on long stalks, shallowly to palmately lobed or toothed, white-woolly to nearly glabrous beneath, green and somewhat hairy above, 4-50 cm long; stem leaves alternate, reduced, represented by parallel-veined bracts 1-6 cm long, more or less white woolly-hairy.
Flowers:
Heads disciform or with ray and disk flowers, several to many in a round- to flat-topped inflorescence, stalks glandular and white-woolly; involucres 6-15 mm tall; involucral bracts oblanceolate to lanceolate, pointed, hairy basally with multicellular hairs, the crosswalls often purple, margins translucent, tips fine-hairy; ray flowers few, whitish or pinkish; disk flowers whitish.
Fruits:
Achenes 5-10-ribbed, glabrous, rarely sparsely long-hairy, 3-4.5 mm; pappus of numerous white, hairlike bristles.
Notes:
Three varieties occur in BC.

1. Leaves merely coarsely toothed or shallowly and obscurely lobed; plants of the subalpine and alpine zones........................ var. frigidus

1. Leaves conspicuously lobed; plants of the lowland to alpine zones.

2. Leaves palmately lobed and usually deeply cleft more than 1/2 way to the leaf base, usually broader than long; plants of the lowland and montane zones........................... var. palmatus (Ait.) Cronq.

2. Leaves lobed, sometimes palmately, but usually not cleft more than 1/2 way to the leaf base, usually longer than broad; plants of the subalpine and alpine zones...................... var. nivalis (Greene) Cronq.

Source:  The Illustrated Flora of British Columbia

Ecology

Ecological Framework for Petasites frigidus

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

Avg

Min

Max
Elevation (metres)
 1062 6 2212
Slope Gradient (%)
 9 0 220

Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]

 341 0 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric] 		4 1 8
Modal Nutrient Regime
Class
 C
# of field plots
 species was recorded in:
 1458
Modal BEC Zone Class
 SBS

All BEC Zones (# of stations/zone) species was recorded in

 AT(6), BAFA(65), BWBS(330), cma(4), CWH(12), ESSF(181), ICH(54), IDF(29), IMA(1), MH(17), MS(108), SBPS(16), SBS(454), SWB(95)

Habitat and Range

Wet to moist ditches, streambanks, meadows and forests in the lowland to alpine zones; var. palmatus is common throughout all BC except the Queen Charlotte Islands and adjacent coast, var. nivalis is common throughout BC, and var. frigidus is frequent in extreme N BC and rare southward; var. palmatus - E to NF and S to MA, MI and CA; var. nivalis - E to PQ and N MN and S to N OR, and var. frigidus - circumboreal, N to AK, YT and NT, Eurasia.

Source:  The Illustrated Flora of British Columbia

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