Flower:

Flower is 1½ to 3 inches across, 12 to 25 yellow rays (petals) and a dark brown center disk ½ to 1 inch in diameter. A plant has 1 to several flowers, each at the end of a 1½ to 6 inch long stalk.

The bracts are flat, wide at the base tapering to sharply pointed tips, with short bristly hairs.

Leaves and stem:

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 wavy edges; the color is a dull green, sometimes bluish-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. Leaf stalks are ¾ to 1½ inches long, longer towards the base of the plant, becoming shorter as leaves ascend the stem. Stems are typically branched, and have a rough texture.

Fruit:

The center disk forms a head of ¼-inch brown seeds. Seeds lack a tuft of hairs but have 2 bristly scales at the tip.

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. It is not uncommon along sandy or gravelly roadsides in mid to late summer. While some references put the plant height at up to 6 feet, I have never seen it more than about 2 feet tall in Minnesota. Prairie Sunflower is distinguished from other MN native sunflowers by its alternate, mostly toothless, often triangular leaves and flowers with a brown, larger than average center disk. The plant most closely resembles Common Sunflower (Helianthus annuus) but in miniature. There are 2 (possibly 3) recognized subspecies: subsp. fallax, restricted to a few states in the southwest US, and subsp. petiolaris, whose range covers much of North America and is present in Minnesota.