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Santa Maria Feverfew, Whitetop Weed or Ragweed Parthenium

Parthenium hysterophorus


Ragweed Parthenium is a coarse, upright, annual plant growing 12-40 inches high. Each flower head which only reaches 3/16 inch in diameter consists of 5 white ray flowers and numerous disk flowers. The leaves are 4-8 inches long and are deeply lobed. The flowers of this plant produce an abundance of pollen, making it a major hay-fever plant. Ragweed Parthenium is found growing in all soils types of the South Texas Plains and the Edwards Plateau regions. It blooms from August to December.


Grass by the path in an urban park.

1 Species ID Suggestions

Santa Maria Feverfew
Parthenium hysterophorus

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1 Comment

gatorfellows 8 years ago

Thanks Chester; I knew you would know :)

Spotted by

Texas, USA

Spotted on Oct 18, 2013
Submitted on Oct 29, 2013

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