Daucus carota is a biennial forb with alternate, finely-divided compound leaves and a large flat-topped inflorescence comprised of many small white flowers. The flowers are arranged in compound umbels and there are pinnately divided bracts at the base of the inflorescence. The outer branches of the inflorescence tend to curl upward as the fruit mature, creating the appearance of a nest--hence one of the common names "bird's-nest weed". It is more commonly known as "wild carrot" by those who consider it a weed and "Queen Anne's-lace" by those who admire the showy inflorescence.
Common garden carrots are cultivars of this species and you can readily see the potential in the large taproot of wild plants. The wild roots if cut or bruised emit a strong odor easily recognizeable as carrot, but they are tough and not sweet so they will not substitute for the horticultural varieties as a vegetable.