Giant Ragweed

Cotyledons emerging from the soil.  Key characteristics: cotyledons are large, spatula-shaped and fleshy.  First true leaves appear unlobed, then develop into three major lobes.

Vegetative plants.  Key characteristics: leaves develop into five major lobes and are hairy.

Flowers.  Giant ragweed is a major contributor of pollen and is partly responsible for allergy problems in the late summer.

Seed.  Seed are yellow-brown mottled with a large central terminal projection surrounded by several shorter projections.  Length is approximately 6.0 to 10.0 mm.

Life cycle: summer annual.