San Diego County, California, US
This plant was growing in a narrow, wet, drainage. It was surrounded with wetland plants, such as, water cress and sedges.
Cirsium is a genus of perennial flowering plants in the Asteraceae, one of several genera known popularly as thistles. They are more accurately known as Plume thistles. These differ from other thistle genera (Carduus, Silybum and Onopordon) in having feathered hairs to their achenes. The other genera have a pappus of simple unbranched hair.