NPSpecies

Data Source: Bilton, 1991 Maxon, 1935;Terrell, 1970

Data Source: Helen Hamilton

Data Source: Helen Hamilton

Park Species Detail: Terrell, 1970: Frequent to common Upland woods; areas 2 (2 (Chain Bridge to Lock 10 parking area opposite Plummer's Island)), ), 3 (3 (Lock 10 to Carderock, north parking lot), ), 4 [Carderock to Cropley (parking area near Angler’s Inn)], 5 (Bear Island), 7 (Great Falls to Swain’s Lock). Fl. Throughout April and May. Bilton, 1991: peak flowering., Park Species Data Source: Bilton, 1991-Ferry Hill;Maxon, 1935;Terrell, 1970;