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

Ambrosia chamissonis (Less.) Greene
silver burweed (silver burr ragweed)
Asteraceae (Aster family)

Introduction to Vascular Plants

© Dawn Hanna  Email the photographer   (Photo ID #10550)

E-Flora BC Static Map
Distribution of Ambrosia chamissonis
Click here to view the full interactive map and legend
Details about map content are available here
New! Click on the map dots to view record details.

Species Information

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



General:
Perennial herb from long, creeping rhizomes; stems leafy, spreading-hairy, stout, branched just below the surface, forming large, lax clumps 20-160 cm tall.
Leaves:
Succulent, mostly alternate, oblong to rounded in outline, about 4-14 cm long with stalks 2-7 cm long, the blades pinnately dissected or rarely simple and toothed, finely whitish- or silvery-haired.
Flowers:
Male (sterile) heads nearly unstalked or short-stalked, 4-6 mm wide, in congested, leafless, terminal spikes about 8 cm long; female (fruiting) heads egg-shaped, 1-flowered;fruiting involucres 1-beaked, 6-11 mm long, glandular and finely hairy burs with 2-4 series of spines or prickles.
Fruits:
Achenes enclosed within the involucral bracts; pappus lacking.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Moist to mesic coastal sandy or gravelly upper beaches and shorelines in the lowland zone; common in coastal BC; S to CA.

Source: The Illustrated Flora of British Columbia

Ecology

Ecological Framework for Ambrosia chamissonis

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) 0 193 1020
Slope Gradient (%) 0 1 5
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
50 92 135
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
1 2 6
Modal Nutrient Regime
Class
A
Number of field plots
 species was recorded in:
12
Modal BEC Zone Class
CWH
All BEC Zones (# of stations/zone) species was recorded in: BWBS(1), CWH(9), MS(2)

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

Ambrosia chamissonis var. bipinnatisecta (Less.) J.T. Howell
Franseria chamissonis Less.
Franseria chamissonis subsp. bipinnatisecta (Less.) Wiggins & Stockw.
Franseria chamissonis var. bipinnatisecta Less.

Taxonomic and Nomenclatural Links

Additional Photo Sources

Related Databases

General References