Root resembles and smells like carrots. Flat-topped umbel of white flowers. Dry fields.
Similar species: Water Hemlock (Cicuta maculata) - grows in wet areas - DEADLY POISONOUS. Bulb-bearing Water Hemlock (Cicuta bulbifera) - grows in wet areas - DEADLY POISONOUS.
Hemlock Parsely (Conioselinum chinense)
Poison Hemlock (Conium maculatum) - DEADLY POISONOUS.
Caraway (Carum carvi)
Water Parsnip (Sium suave) - Flower umbel similar; grows in wet areas; leaves very different.
Japanese Hedge Parsley (Torilis japonica) - Flower umbel is very open and consists of several small clusters of flowers.
I have provided a lot of photos of this plant, in order to help you distinguish it from its poisonous look-alikes. Although this plant is edible, be very careful not to confuse Wild Carrot with other similar species, some of which are DEADLY POISONOUS. Be sure that the plant you think is Wild Carrot actually smells like carrots. And that it is growing in a dry field.