Hi, I’m hoping for some help identifying this ground cover. It looks a little like poison ivy, but it has green, herbaceous stems that come right up from the ground—no obvious vine—with opposite leaves in groups of up to 5, as you can see on the photos. I think it may be an ornamental ground cover from my neighbor’s yard, but I’m not sure.
Montgomery County Maryland
This appears to be Bishop's Weed, a.k.a. Goutweed (Aegopodium podagraria), a common invasive weed in our area. This is sometimes (or has been) sold as garden groundcover in its variegated form, but often re-seeds as solid-green plants. Responsible garden centers would not stock it, but it has been in horticulture long enough that a planting of this in the neighborhood may have been around for a long time.
https://extension.umass.edu/landscape/weeds/aegopodium-podagraria It is established in several MD counties: https://www.marylandbiodiversity.com/viewSpecies.php?species=2330
Removing it by pulling it up can be challenging since bits of rhizome left behind can re-sprout, though repeated removal will eventually starve-out the plant. The plants could also be starved of light by a covering of some sort meant to block out the light, but if they are interspersed with desirable plants, this may not be the most practical choice. Early-season (spring) treatment with root-killing herbicide, such as glyphosate, may be needed in areas too large or difficult to hand-pull or hoe. If chosen, use caution, as non-selective herbicides will harm any plant they contact. If spraying is too risky, the herbicide could be "painted" on with a brush or painter's-type sponge (essentially a foam sponge on a stick) dedicated to that use. (Hardware stores should have these.)
Thanks for the helpful reply!