Helianthus occidentalis ssp. occidentalis

Native

Dry to moderate moisture. Prairies. Full sun.

July to September

Yellow ray florets, yellow disk florets.

2′ to 5′

This is a 2′ to 5′ tall, erect, perennial forb that rises from a rhizome.

The stems are erect, often reddish, and hairy near the bottom, hairless above.

The leaves are mostly basal. The basal leaves are egg-shaped to lance shaped, 2″ to 8″ long, ⅔″ to 2¾″ wide, and taper gradually to a point. They are on stalks 1″ to 4″ long. The bases are wedge shaped and narrowly triangular and taper to a point. The margins are untoothed or weakly toothed. There are 3 to 8 pairs of opposite stem leaves. Stem leaves are much smaller and have untoothed margins. Basal and stem leaves are rough to the touch.

The inflorescence is several flower heads in loosely-branched clusters at the ends of the stems.

The flower head is 1½″ to 2¾″ wide and has 8 to 14, yellow ray florets. The underside of the rays are densely dotted with glands. The disk is cone-shaped, ⅜″ to ⅔″ wide, and has 50 or more yellow disk florets.