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

stem conspicuously pubescent below the inflorescence with short white hairs

involucre bracts narrow, mostly with loose acuminate tips

involucre bracts covered with short white hairs, sometimes ciliate toward the base

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