From the Mustard Family (Brassicaceae). One easy differentiator: it begins flowering in April whereas Black Mustard generally starts in June. The Black Mustard flowers are a richer yellow-orange as opposed to the pale/bright yellow of the Winter Cress. Leaves become smaller and less lobed toward the top of the plant. Also called Yellow Rocket, it is often found in damp fields, roadsides, hay fields and brooksides.