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

Crepis occidentalis Nutt.
western hawksbeard (largeflower hawksbeard; Western hawksbeard )
Asteraceae (Aster family)

Introduction to Vascular Plants

© Thayne Tuason  Email the photographer   (Photo ID #76397)

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Distribution of Crepis occidentalis
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Species Information

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General:
Perennial herb from a taproot and stem-base; stems erect, 1-3, densely and closely grey-short woolly-hairy, or nearly glabrous in age, often glandular-stiff-hairy above, sometimes with black glandular bristles above, 5-40 cm tall.
Leaves:
Basal leaves long-stalked, toothed, with the teeth pointing backwards, or deeply pinnately cut with lanceolate or linear toothed lobes, these entire, abruptly sharp-pointed or with long-pointed tips, mostly 1-3.5 dm long, the blades grey-short woolly-hairy, or nearly glabrous in age; lower stem leaves similar to the basal leaves, becoming reduced, linear and entire upwards.
Flowers:
Heads with strap-shaped flowers, 2-25 in a flat-topped inflorescence; involucres 11-19 mm tall, cylindric or bell-shaped; involucral bracts grey, short woolly-hairy with or without gland-tipped hairs, the longest outer ones usually less than 1/2 as long as the inner, triangular or egg-shaped, abruptly sharp-pointed, rarely linear, the inner ones lanceolate, abruptly sharp-pointed or with long-pointed tips with membranous margins; ray flowers yellow, 16-19 mm long.
Fruits:
Achenes, light to dark brown, 6-10 mm long, spindle-shaped, 10- to 18-ribbed, only slightly tapering to a slender tip; pappus white to yellowish-white, of copious, soft, hairlike bristles.
Notes:
Three subspecies, sometimes difficult to separate, occur in BC.

1. Involucres with at least some gland-tipped hairs.

2. Largest heads 18- to 30-flowered, with 10-13 inner involucral bracts.................. ssp. occidentalis

2. Largest heads 12- to 14-flowered, with 8-9 inner involucral bracts....................... ssp. costata (A. Gray) Babc. & Stebb.

1. Involucres without gland-tipped hairs..................... ssp. pumila (Rydb.) Babc. & Stebb.

Source: The Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Yellow
Blooming Period:
Late Spring
Fruit/Seed characteristics:
Colour: Brown
Present from Spring to Summer
Source:  The USDA

Habitat / Range

Dry grasslands and shrublands in the steppe zone; all subspecies frequent (ssp. costata, ssp. occidentalis) or rare (ssp. pumila) in SC BC, frequent in SE BC (ssp. occidentalis); E to S AB and SD, S to NM and CA.

Source: The Illustrated Flora of British Columbia

Ecology

Ecological Framework for Crepis occidentalis

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

Minimum

Average

Maximum

Elevation (metres) 500 833 1050
Slope Gradient (%) 8 40 65
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
150 261 350
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
1 2 4
Modal Nutrient Regime
Class
C
Number of field plots
 species was recorded in:
8
Modal BEC Zone Class
BG
All BEC Zones (# of stations/zone) species was recorded in: BG(5), IDF(3)

Climate

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

Crepis occidentalis var. nevadensis Kellogg p.p.
Crepis occidentalis var. nevadensis Kellogg
Psilochenia modocensis subsp. subacaulis (Kellogg) W.A. Weber
Psilochenia occidentalis subsp. conjuncta (Jeps.) W.A. Weber

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References