Helianthus couplandii

Prairie Sunflower

Douglas Provincial Park
24-aug-2002

I have found that neither flora easily distinguishes between Helianthus and Rudbeckia (Rudbeckia hirta is Black-eyed Susan) in their keys.  However, they do note that the receptacles of Rudbeckia are more conic.

Couplandii Characteristics

receptacle flat or nearly so

disk purple or dark brown

scales between disk florets each with tuft of hairs

 

Helianthus Characteristics

receptacle flat or convex, not conic or columnar

receptacle with chaffy scales between the florets

flower heads with both tubular and ray florets

rays conspicuous

ray florets yellow