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

Sonchus oleraceus L.
annual sow-thistle; common sowthistle; common sow-thistle
Asteraceae (Aster Family)

Introduction to Vascular Plants

© Jim Riley  Email the photographer   (Photo ID #27932)
Distribution of Sonchus oleraceus
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Species Information

Click on the image below to view an expanded illustration for this species.



Illustration Source:  The Illustrated Flora of BC
General:
Annual herbs 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, weakly or scarcely prickly-margined, lowermost stalked, backward-swept pinnately cut to occasionally merely toothed, 6-30 cm long, 1-15 cm wide, uppermost lobed with sharply pointed ear-lke lobes.
Flowers:
Heads with strap-shaped flowers, several on sometimes glandular stalks in an open, flat- or round-topped inflorescence, relatively small, commonly 1.5-2.3 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 3-5 evident to rather obscure longitudinal ribs on each face, cross-wrinkled; pappus of white hairlike bristles.

Source:  The Illustrated Flora of British Columbia

Ecology

Ecological Framework for Sonchus oleraceus

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, 2008)
Site Information
 Value / Class

Average

Minimum

Maximum
Elevation (metres)
 657 283 1097
Slope Gradient (%)
 27.2 0 50

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

 169.2 70 210
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric] 		3.0 2 5
Modal Nutrient Regime
Class
 Poor
Number of field plots
 species was recorded in:
 9
Modal BEC Zone Class
 IDF

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

 BG(2), CDF(1), CWH(2), IDF(3), PP(1)

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.

Habitat / Range

Mesic to dry roadsides, disturbed areas and gardens in the lowland and lower montane zone; frequent on S Vancouver Island, infrequent elsewhere on the coast; introduced from Europe.

Source:  The Illustrated Flora of BC

Taxonomic and Nomenclatural Links

Flora North America treatment for Asteraceae
 Flora North America treatment for Sonchus oleraceus
Genetic information (NCBI Taxonomy Database)
 International Plant Names Index
 Taxonomic Information from the Missouri Botanical Garden
 Vascular Plant Type Database, New York Botanical Gardens
 Integrated Taxonomic Information System

Additional Photo Sources

Burke Museum of Natural History's Image Collection
 Images From CalPhoto
UT Austin's Native Plant Database
 Google Image Search
 Flickr Image Search

Related Databases

The Global Invasive Species Database
 FDA Poisonous Plant Database

General References

Google Scholar Search
Family References
 General Botanical References for BC
Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2013. E-Flora BC: Electronic Atlas of the Plants of British Columbia [eflora.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 5/22/2013 6:43:16 AM ]
Disclaimer: The information contained in the E-Flora atlas pages is derived from expert sources as cited in each section. This information is scientifically based. E-Flora also acts as a portal to other sites via deep links. As always, users should refer to the original sources for complete information. E-Flora BC is not responsible for the accuracy or completeness of the original information.
E-Flora BC: An initiative of the Spatial Data Lab, Department of Geography UBC, and the UBC Herbarium.