[Members of the
Sunflower Family with Flower Heads like Sunflowers or Daisies in the Columbia River Gorge of Oregon and Washington]
Horseweed, Canada Fleabane, Canadian Fleabane
Conyza canadensis
Synonyms: Conyza canadensis var. canadensis, Conyza canadensis var. glabrata, Erigeron canadensis
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Two images showing the involucre as well as the tips of the tiny ray flowers of horseweed. There are a few minute hairs on the involucral bracts, but they are essentially glabrous. Note the tiny ring of white ray flowers as well as the yellow disk flowers of horseweed. The similar Conyza bonariensis is more copiously haired on the involucre. Photographed along the old highway about one mile east of Celilo, OR..........September 1, 2007.
The photo above shows a close-up of the numerous narrow stem leaves of horseweed.......September 1, 2007.
The photograph above shows a view of horseweed as seen in disturbed soils alongside the old higway about one mile east of Celilo, OR........September 1, 2007.
Paul Slichter