[Wildflowers of the Sunflower Family with Button-like Flower Heads in the Columbia River Gorge]

Annual Bursage, Annual Bur-sage, Annual Burweed , Bur Ragweed, Flat-spine Bur-ragweed

Ambrosia acanthicarpa

Synonym: Franseria acanthicarpa

Annual Bursage, Annual Burweed , Bur Ragweed, Flat-spine Bur-ragweed: Ambrosia acanthicarpa (Synonym: Franseria acanthicarpa)

The photo above shows the inflorescence and a stem leaf of bur ragweed as seen along Washington Highway 14 at milepost 91 above the Avery Sand Pit.......October 7, 2006.

Leaf of Annual Bursage, Annual Burweed , Bur Ragweed, Flat-spine Bur-ragweed: Ambrosia acanthicarpa (Synonym: Franseria acanthicarpa)

The photo above shows a close-up of the pinnatifid stem leaf of bur ragweed as seen along Washington Highway 14 at milepost 91 above the Avery Sand Pit........October 7, 2006.

Paul Slichter