Helianthus maximilianii

Narrow-leaved Sunflower

Southeast of Sedley
30-August-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.

Maximilianii Characteristics

disk yellow or light brown

receptacle convex or low conical

 

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