When we moved to our current home in 2003, we moved one county to the west. It was about a 20 minute drive from our old home to our new one. Most of the same weeds grew in our new yard, but there was one I'd never seen before. I tried to research it online, but I never found it. I searched through every weed database I could find, but it wasn't there.
One day, in my online searches, I came across the Maryland Cooperative Extension Service/University of Maryland Home and Garden Information Center. I was able to "ask the expert" and I found out my weed, which was all over the place, was hairy bittercress. Once I had the name, I had a wealth of information at my fingertips.
Here's what it looks like:
It's a winter annual that starts showing up in very late fall or early winter. By the time the warm days of spring roll around, it's already throwing seed all over the place. And yes, I said throwing because the seed capsules literally explode. You do not want this weed in your garden, so if it shows up, get rid of it early.
Here's some information about this pest.
Scientific name: Cardamine hirsuta
It's a member of the brassica family and it has a tangy flavor. When eradicating it from your yard, pull it up and add the leaves to your salad. Rosettes range in size from 2 to 6 inches across. Stem fragments can root and grow, so make sure you get the whole thing when you pull it up.
Although most of what I've read says it's common to dry, sunny places, I have this weed all over my yard. It grows in the sun and in the shade, and it seems more common in areas that are slightly moist.
It grows in much of the United States except the central and upper midwest. It's also found in the far eastern and western provinces of Canada. Some information I've read indicates this weed is not native to the US, and it likely originated in Europe or the UK.
If this pesky weed is showing up in your garden now, don't wait for spring. Put that hoe to good use and get rid of it before it starts tossing seed.
Here are some links for additional information.
Additional information from a UK site