A: The weed is hairy bittercress, Cardamine hirsute, and it typically is a winter annual but it will continue to grow in shaded, moist areas if it is not pulled or controlled. It produces large numbers of seeds which have a high germination rate. This, of course, means almost all the seeds become adult plants. It would be nice to have this kind of production rate on our vegetables and flowers! The basal leaves somewhat resemble parsley and it has a small cluster of white flowers at the top. Hairy bittercress often comes with contain plants so consider removing any weed from pots before you bring them home. I always return them back to the nursery and tell them I will not pay for plants I do not want! No one every laughs but better to dispose of them at the nursery then let them become a problem in your landscape. There is another weed, very similar looking to the Hairy bittercress but its leaves are much smaller and it prefers dry soils. Neither weed is a bonus in the landscape.