wild, wood, or spotted
Geranium carolinianum var. carolinianum
These are the only two native geraniums easily found in the Maryland piedmont. There’s a third species (G. bicknellii) that might be present, and a fourth (G. robertianum) that is listed S1, so spotting it is unlikely. There are also half a dozen or so alien geraniums present in the state.
Carolina cranesbill is found in all US states except Colorado, and most of Canada except the far north and the maritime provinces. It is listed as weedy by some authorities. It grows best in poor soils, which may explain why I first found it growing from cracks in the concrete curb in the Carderock parking lot. [right] The other place I’ve spotted it is on the rocky promontories that jut into the Potomac downstream of Carderock.
Wild geranium is found in the the eastern US, most of the south and midwest, and somewhat into the great plains states. It prefers moister, richer soils than Carolina cranesbill; watch for it in open woodlands in the piedmont. Wild geranium is lovely in the home garden, and so far in my garden it’s been rabbit-resistant. There are native plant sellers around who carry it. The one I planted last spring has about tripled in size and is blooming profusely.