The two photos are of different but similar plants. They each have a single stalk and fernlike leaves. One has a bloom.
Agree with Sceptridium spp., though this genus is usually included in Botrychium. Try keying them out in Flora N America here: http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=104332 I see no flowers - that is a spore-bearing frond in the second pic.
Thanks to all for replying. I checked out images of sceptridium and botrychium and the plants I saw very much resemble them. They are growing in a wooded area near Annapolis, Maryland, USA.