Yellow Rocket (Common Winter Cress)
A leafy, much-branched weed to 2 feet tall. Flowers many, crowded, bright yellow, with the typical mustard-family configuration of 4 petals in a crosslike formation, about 3/8 inch across. Blooms April-June. Leaves featherlike, the terminal section oval or circular and much larger than the sections below; the lower leaves on long petioles; the stem leaves often sessile (stalkless). Fruit a long seedpod (technically, a silique); these form at the bottom of the cluster as new flowers open at the tips of the flower stalks.