Credit: Mary Konchar Eaglet in Loblolly Pine Nest

Blackwater Refuge contains approximately 165 species of threatened or endangered plants, and the Refuge is noted for having the northernmost expanses of three-square-bulrush-dominated marshes in the country.

Olney three-square blooms from June into September. The tubers of three-square are an important food source for ducks, geese, and muskrat. In addition, waterfowl feed on the plant's seeds, muskrats use the leaves for building their lodges, and songbirds and ducks use the densely growing stands as protective cover for nesting.

Blackwater's forests are mostly loblolly pines mixed with small stands of oak. The Eastern Shore is the northern limit of the loblolly pine's range. Loblollies can be identified by their long, twisted, yellowish-green needles growing in bundles of three.

Loblolly pines are important to many species including the bald eagle, which uses the trees as perches and nesting sites. Also, seeds of the loblolly are an important food source for the endangered Delmarva fox squirrel population. Blackwater Refuge protects the largest remaining population of the squirrel with about 550-600 animals living at the Refuge.

Among the many other useful plants at Blackwater Refuge is the wax myrtle or northern bayberry, which grows close to the marsh edge. Birds feed on wax myrtle berries when other food supplies are depleted.

Also, a woody vine called common greenbriar serves many purposes for wildlife. White-tailed deer feed on its leaves and songbirds enjoy the dark blue berries. Also, birds, rabbits and other small rodents use the dense thickets for protective cover.