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

Madia sativa Molina
Chilean tarweed (coast tarweed)
Asteraceae (Aster family)

Introduction to Vascular Plants

© Adolf Ceska  Email the photographer   (Photo ID #11248)

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Distribution of Madia sativa
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Species Information

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Aromatic annual herb from a taproot; stems erect, simple, often branched above, glandular, 0.2-1.0 m tall.
Basal leaves lacking; stem leaves often with clusters of smaller leaves in their axils, alternate, linear or linear-oblong, entire or slightly toothed, unstalked, glandular, 3-18 cm long, 3-12 mm wide; lower stem leaves crowded, soon deciduous.
Heads with ray and disk flowers, numerous in an elongate inflorescence; involucres egg-shaped or broadly urn-shaped, 6-12 mm tall; involucral bracts rounded on the back, glandular; ray flowers yellow, 8-13, 3-7 mm long; disk flowers yellow, 11-14, fertile.
Ray achenes flattened, 2.5-5 mm, glabrous, sometimes mottled, disk achenes sometimes 1-nerved; pappus lacking.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Dry roadsides and disturbed areas in the lowland and lower montane zones; infrequent in S BC, possibly introduced; native range from N WA to CA, disjunct in Chile.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Madia sativa

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




Elevation (metres) 130 453 839
Slope Gradient (%) 5 43 84
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
30 195 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
0 2 5
Modal Nutrient Regime
Number of field plots
 species was recorded in:
Modal BEC Zone Class
All BEC Zones (# of stations/zone) species was recorded in: CDF(2), CWH(6), ICH(1)


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 cool mesothermal.

Synonyms and Alternate Names

Madia capitata Nutt.
Madia sativa subsp. capitata (Nutt.) Piper
Madia sativa var. congesta Torr. & A. Gray

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References