This is a picture of Taphrina polystichi on a Christmas Fern at Watkins Regional Park in Prince George's County, Maryland.
This is a picture of Dasineura pellex on an ash leaf at Watkins Regional Park in Prince George's County, Maryland.
This is a picture of Dasineura investita on a wood nettle leaf at Watkins Regional Park in Prince George's County, Maryland.
Multiple larvae inside the gall on young leaves of Acer negundo.