Taxon  Report   4065    
Hemizonia congesta  DC.
Hayfield tarweed
Hemizonia congesta
© 2015 Vernon Smith
Photos from
CalPhotos / Calflora
Hemizonia congesta
© 2018 Stacie Wolny
Hemizonia congesta
© 2018 Stacie Wolny
Hemizonia congesta, a dicot, is an annual herb that is native to California, is also found outside of California, but is confined to western North America.

Interactive Distribution Map

Observation Hotline
(observation details)

point, line, or polygon

Plant Characteristics
and Associations

Bloom Period
Hemizonia congesta
© 2018 Stacie Wolny
Communities: Valley Grassland, Northern Coastal Scrub, Foothill Woodland, Southern Oak Woodland
Name Status:
Accepted by JEF + PLANTS

More information about  Hemizonia congesta
Nursery / seed vendor availability from CNPLX
This plant is available commercially.
Landscaping information from Calscape
Photos on Google Images
UC Integrated Pest Management Weed Photo Gallery
(profile of this plant as an agricultural weed)

Jepson eFlora

Records from the Consortium of California Herbaria

ITIS Original Publication citation


Search the International Plants Names Index

Search (Flora of North America)

website references from Google

Suggested Citation
Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals, including the Consortium of California Herbaria. [web application]. 2019. Berkeley, California: The Calflora Database [a non-profit organization]. Available:   (Accessed: Jan 18, 2019).