- Bethesda2
- Found at Cove Point Marsh, along the Chesapeake Bay.2
- Glen Echo2
- Harford2
- High Island.2
- Negro Mt. Bog, 6 mi SW of Grantsville2
- Negro Mt. Bog, 6 mi. SW of Grantsville2
- Patuxent Research Refuge, Plot 16862
- Patuxent Research Refuge, Plot 16872
- Patuxent Research Refuge, Plot 36412
- Patuxent Research Refuge, west shore of Cash Lake, Plot 43842
- Region between Leornardtown & Millstone.2
- Salisbury2
- Sheppard Asylum2
- Talbot2
- West shore of Cash Lake, Patuxent Research Refuge2
- Accokeek, Piscataway Park easement, off the west side of West Auburn Road .8 km from Bryan Point Road.1
- Across Rt 5 and south of Buzzy Country Store near Scotland.1
- Adelphi Rd., 1 1/2 miles NE. Adelphi1
- Allegheny Plateau, wetlands parallel to the Youghigheny River, north of Gap Falls.1