Prairie Sunflower (Helianthus petiolaris): yellow Minnesota wildflowers

Prairie Sunflower

Plant Info
Also known as:	Plains Sunflower
Scientific name:	Helianthus petiolaris
Family:	Aster (Asteraceae)
Life cycle:	annual
Origin:	native
Habitat:	sun; dry sandy soil, prairies, along roads
Bloom season:	summer to early fall
Plant height:	1 to 4 feet
USDA PLANTS database:	Minnesota county distribution map
Spotted in Ramsey County at:	Long Lake Regional Park

Pick an image for a larger view. Most image enlargements are 50-100KB, though some may be larger. See the glossary for icon descriptions.

Flower:: Flower is 1½ to 3 inches across, 12 to 25 yellow petals (ray flowers) and a dark brown disk. Each plant has 1 to a few flower heads, each at the end of a stem 3 to 4 inches long.
The bracts are flat, wide at the base tapering to sharply pointed tips, with short bristly hairs.
Leaves and stem:: The leaves are rather variable—they may be triangular, oval, or shaped like the head of a spear. All leaves have a rough texture and somewhat curly edges; the color is a dull green. There are 2 prominent lower veins that run parallel to the main center vein. There may be a few shallow teeth along the edge, but leaves are mostly toothless. The leaf size is variable depending on the shape. Elongated spear-shapes may be up to 6 inches long and 1 inch wide. Triangular leaves are up to 3½ inches long and 2 inches wide. The leaf stems are fairly long, and longer towards the base of the plant. The main is stem is woody and has a rough texture.
Fruit:: A round head of ¼-inch brown seeds.
Notes:: Prairie Sunflower can grow in clumps that make it look like a small bush, but it is not unusual to see single plants scattered around.