The scientific name for Hawkweed is Hieracium. It is a member of the sunflower family. There are more than 10,000 species and subspecies of Hawkweeds. They, like their cousins the dandilions, reproduce asexually. The seeds are genetically identical to their mother, meaning they have no father since there are only female hawkweeds. Yes, they are clones, in your backyard.
A close up of the hawkweed leaves is what attracted me to them this fall. The leaves are covered with tiny hair-like appendages called trichomes. The function of these trichomes is probably to trap moisture, although some plants use them to secrete sticky substances (think honey-dew and fly catchers) to catch prey or use the trichomes protect the leaf from predation. Think prickly bean leaves.
Hawkweed is an introduced species to the U.S., it is native to northern, central, and eastern Europe and was believed to be introduced to the United States in 1800s as an ornamental. It is an early succession plant, so its mostly found in empty lots, disturbed areas or meadows. Around here it is not considered a pest plant, but in meadows, fields and pastures used for feeding animals it may reduce forage quality since its not highly nutritious.