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

Sonchus asper (L.) Hill
prickly sow-thistle (spiny sowthistle)
Asteraceae (Aster family)

Introduction to Vascular Plants

© Adolf Ceska  Email the photographer   (Photo ID #20969)

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Distribution of Sonchus asper
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Species Information

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General:
Annual herb from a short taproot; stems erect, solitary, few-branched above, glabrous, hollow, exuding milky juice when broken, 0.1-1 m tall.
Leaves:
Basal leaves lacking; stem leaves alternate, prickly- margined, lowermost with stalks but not so clearly divided (as in S. oleraceus) into blade and stalk, more or less egg-shaped, uppermost deeply pinnately cut to egg-shaped and lobeless with rounded, clasping flanges at the base, 6-30 cm long, 1-15 cm wide.
Flowers:
Heads with strap-shaped flowers, several on sometimes glandular stalks in an open, flat-topped inflorescence, relatively small, commonly 1.5-2.5 cm wide in flower; involucres 9-14 mm tall; involucral bracts lanceolate, tapering to a slender tip at the apex, glabrous except for some spreading, gland-tipped hairs; ray flowers yellow.
Fruits:
Achenes 2.5-3 mm long, with 3 or rarely 4-5 conspicuous longitudinal ribs on each face, not wrinkled; pappus of white hairlike bristles.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Mesic to dry roadsides, disturbed areas and gardens in the lowland, steppe and montane zones; frequent in all but N regions of BC; introduced from Europe.

Source: The Illustrated Flora of British Columbia

Ecology

Ecological Framework for Sonchus asper

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) 204 410 1270
Slope Gradient (%) 0 14 70
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
45 223 350
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
1 4 6
Modal Nutrient Regime
Class
D
Number of field plots
 species was recorded in:
84
Modal BEC Zone Class
CWH
All BEC Zones (# of stations/zone) species was recorded in: BG(6), CWH(66), IDF(4), PP(8)

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

Sonchus asper subsp. asper
Sonchus asper subsp. glaucescens (Jord.) J. Ball
Sonchus nymanii Tineo & Guss.

Taxonomic and Nomenclatural Links

Additional Photo Sources

Related Databases

General References