Wildflowers in bloom at Manassas National Battlefield Park
NPS Photo; Courtesy of Gregory Perrier
Virginia Spring Beauty Claytonia virginica
NPS Photo
Several different types of plant communities occupy the 5,000 acres of land at Manassas National Battlefield Park. Hundreds of acres of the park are maintained as the historic agrarian landscape that existed in 1861. Agricultural hay leases preserve an authentic cultural perspective for the enjoyment of the public. The native, warm season grasses also provide an excellent habitat for wildlife. Open fields are covered in native grasses, wildflowers, and shrubs.
The woodlands are made up of basic oak-hickory forests, acidic oak-hickory forests, mesic forests, mountain bottomland forests, mountain swamp forests, upland depression swamp forests, eastern white pine hardwood forests, and Virginia pine- Easter red cedar successional forests.
The park hosts over 700 kinds of vascular plants; 186 monocot angiosperms, 500 dicot angiosperms, 16 pteridophytes, and 4 gymnosperms carpet the premises. The abundance of multiple plant communities within the park represents a healthy ecosystem that is capable of supporting a diverse range of wildlife.
Manassas National Battlefield
NPS Photo
Invasive Plant Species at Manassas
See below for a list and information on some of the more common invasive plant species found at Manassas NBP.
These invasive shrubby trees can be found in semi-dry to dry forests, woodlands, old fields, fencerows, and roadsides. They are most abundant in open habitats but are shade-tolerant and now frequent the understory of forests and woodlands.
Autumn olive was originally planted as a landscaping and wildlife resource, but it is now abundantly invasive in both disturbed and natural habitats. They are widespread throughout the park and there are ongoing efforts taking place to manage the population.
Leaves are oval shaped with smooth edges and distinct silver undersides. Autumn olive is one of the first to grow leaves and last to drop them in the fall, making it easily distinguishable in autumn.
Flowers are trumpet-shaped, white, and cluster in groups of 5-10.
Fruits are small red berries dotted with silver to brown scales, maturing from August to September. They are edible and are used in a variety of recipes.
Autumn olive is able to persist in poor sites partly because it is able to create its own absorbable form of nitrogen. It is tolerant of salinity, extreme pH, and heavy metals.
This invasive perennial can be found along road banks, forest edges, fields, open rocky streamsides, and disturbed floodplains.
Leaves are separated into 10-22 small egg-shaped leaflets. They often have a small, spiked point at the tips.
Flower clusters are rounded and made up of ~25 pink flowers. The individual flowers are typical shape for the pea family and are a darker pink on the upper petals and a pale pink to white on the lower petals.
Crown vetch persists from erosion-control plantings but have sometimes escaped far from plantings, especially in sandy soils.
Fruits are finger-like clusters of green, thin pods that ripen into a deep reddish brown. Each pod contains up to 12 seeds.
Crown vetch is visually similar to native vetches, so confirm identification before removing.
This tree can be found in disturbed forests, old fields, fencerows, road banks, and urban woodlots.
It is highly invasive in both disturbed and natural habitats. Huge numbers of wind-dispersed seeds germinate frequently and repeatedly in older mesic and dry-mesic forests of Virginia.
Once it is established in a disturbed forest, this species can be very hard to eradicate. Its leaves are allelopathic, which prevents other plants from growing around the tree. It has abundant seed production and root suckering.
Leaves are arranged into large pinnately compound leaflets with serrated edges. When crushed, leaves emit an unpleasant, burnt peanut butter smell.
Tree of Heaven is an important food source for the invasive spotted lanternfly. The insects flock to trees to feed on sap and emit a sugary substance, called honeydew, as a byproduct. Honeydew attracts bees, flies, and wasps, and many times these trees are surrounded by flying insects.
This invasive biennial can be found in fields, pastures, roadsides, clearings, and other open, weedy habitats. As a biennial, the plant forms a rosette the first growing season and then shoots up and produces flowers in the second.
Stems can range from 1.5-6.5ft in height and spiny wings run up the sides.
Leaves are alternate, hairy, lobed, and have large spikes on the edges. Stiff bristles cover tops of leaves.
Flowers are pink or purple and have a puff-ball appearance. Bull thistle reproduces from seeds which only germinate in the spring.
Bull thistle is similar in appearance to native thistles. Be sure to confirm identification before removing – one indicator of an invasive thistle is being green on both sides of the leaves, while native thistles tend to have white and wooly undersides.
Thistles are a favorite food source of goldfinches.
This invasive annual grass can be found in floodplain forests, swamp hummocks, mesic to dry-mesic upland forests, wet flatwoods, shaded clearings, and other moist, often shaded, disturbed habitats.
Japanese stiltgrass forms dense carpets that prevents native species from establishing. They often cover moist or wet floodplains and stream bottoms.
Leaves are slender and lance-shaped. Each leaf blade is between 1 and 3 inches in length. A silvery stripe runs down the leaf, slightly off-center.
Stems are thin, wiry, and interconnected by a horizontal runner stem emerging from the roots. Each stem is supported by small, stilt like prop roots, giving the species its name. Dead stems remain over winter, forming a dense, matted layer, or thatch, over the soil.
When in bloom, a three-branched flower spike emerges and eventually matures into seeds. Seedhead spikes are 1-2 inches in length.
This vine is nearly ubiquitous in wet to dry forests, old fields, disturbed floodplains, and various open habitats.
It is shade-tolerant and very invasive in many natural community types
Can run up to 5+ meters long
Woody, trailing, climbing
Twigs can range from hairless to densely hairy
Leaves are elliptic to oblong in shape with smooth edges. Evergreen
Flowers are very fragrant and are white or pink becoming yellow, resemble long tubes
Berries are black and are 4-6mm long.
This shrub or high-climbing vine can be up to 20m long. It is very invasive in mesic forest habitats.
Most wisteria in this area is a hybrid of Chinese Wisteria (Wisteria sinensis) and Japanese Wisteria (Wisteria floribunda)
Leaves are arranged into leaflets, with 7-13 leaflets per leaf.
It was originally cultivated for landscape purposes, but has since escaped to forests, borders, and fencerows. It is shade-tolerant, which makes it very invasive.
This vine is vigorously colonial and can be scrambling or climbing. It can be found in various wetland and upland forests, clearings, old fields, pastures, fencerows, roadsides, and other disturbed habitats.
Stems can reach 3m in length and are smooth. A defining feature of this species are the small eyelash-like hairs at the base of leaves.
Leaves are serrated, or have jagged edges. Leaves are usually green, but new leaves can be spotted with pink or red.
Produces many flower clusters that can be white, red, or pink. Flowers have five petals and bright yellow pollen. Fruits persist through the winter and are small, shiny, and red, darkening over time.
This extremely invasive species was originally introduced for landscape purposes, as a living fence, for erosion control, and to provide food and cover for wildlife. It can produce dense thickets that degrade natural environments and reduce native plant and wildlife diversity.
This invasive shrub can be found in mesic to dry forests and old fields.
It typically ranges from 0.5-4ft in height and is densely branched with thorns.
Leaves taper to a narrow base and have smooth edges. Leaves can be shiny green to burgundy in the fall.
Flowers are yellow and are solitary or in groups of 2-4. Berries are small and red with a round/elliptic shape.
Originally used as a landscaping shrub and has since become a problematic invasive, especially near urban areas. It produces many seeds that are easily spread by birds.
This perennial grass can be found in mesic upland forests and shaded clearings. It is locally abundant and can cover many acres.
Leaves are very wavy; similar shape to deertongue (Dichanthelium clandestinum), but with distinct waves.
This invasive grass was first found in Maryland in 1997 and has since been established throughout the Piedmont region and locally.
Seeds stick to shoes, clothing, tires, animal fur, and paws, and are easily spread by people and animals.
Hand-pulling or digging plants out before they go to seed is the best control method.
