Yellow hawkweed is one of the worst pasture weeds in the New England states. It spreads by rhizomes, stolons, and seeds. The leaves are very hairy on both surfaces. The flower stalks are 1 to 3 feet tall, and the outsides of the flower heads are covered with black glands. In the Pacific Northwest there are also two common native hawkweeds which are similar to yellow hawkweed. These are Hieracium canadense and Hieracium umbellatum. They can be distinguished by the fact that the basal leaves are smaller than the middle stem leaves while Hieracium pratense is the opposite.