Prince William Forest Park - Plants (U.S. National Park Service)

Spring Understory

The park contains a wide array of plant species. There are at least two distinct types of forest ecosystems in the upland areas of the park. On the ridges and upper slopes is a mixed oak forest, and on the lower slopes, above the floodplain, is a mesic hardwood forest. Beeches, which are found in this area, require undisturbed interior environments for their best development into a forest. Some uncommon or rare tree species are interspersed, including butternut, bigtooth aspen, black walnut, swamp white oak, and cottonwood, as well as floodplain species like American beech, box elder, and sycamore. Several of these species are at their distributional limits in the park, attesting to the fact that the park is in a transition zone between northern and southern climates and between eastern and western physiographic provinces. The park contains several rare communities, including a seepage swamp, remote stands of eastern hemlock, and several populations of rare plants. As surveys are conducted, other rare communities may be located in the park. Understory trees and vegetation, including dogwood, redbud, ironwood, mountain laurel, American holly, Solomon's seal, spotted wintergreen, and sassafras, are found throughout the forest. Ferns, mosses, vines, briers, and numerous wildflowers form the groundcover. Cardinal flower and Hercules club are common in the park, although uncommon and protected elsewhere. The small-whorled pogonia, a federally listed threatened species, has been identified in the park. Because of its rarity, specialized habitat criteria, and proximity to developed areas, the management of this species is critical to ensure its continued survival.