The Early Detection and Rapid Response (EDRR) program focuses on
locating new populations of certain invasive species through
methodical surveys and then eradicating these species before they cause
serious ecological harm in the county's parks. A key component of EDRR
is adding information to Early Detection and Distribution
(EDD) maps which track invasive species across the
country. EDRR volunteers work under the direction of a volunteer survey
leader and have the opportunity to work in a park near them. Because of
the survey work, volunteers need to have some experience identifying
local native and invasive species. This volunteer led program gives
people with botanical knowledge an opportunity to connect with each
other and also a chance to give back to the community by working to
protect the county's bountiful natural resources.
The goals of this program include:
Recruiting volunteer survey leaders and support staff
Each survey leader will hold at least 11 survey events a year
Record and document new invasive species population
Eradicate these populations when necessary
Adding to the EDD maps database
Invasive Species Watch List
Wavyleaf basketgrass (Oplismenus hirtellus)
Wavyleaf basketgrass is a low-lying, trailing perennial grass that
is less than one foot tall. Its flat leaf blades are about one-half
to one inch wide and 1.5 to 4 inches long, have elongated pointed
tips and are rippled. It is noticeably hairy where the leaf attaches
to the stem, although the hairs are very short. Individual stems
connect to each other underground. When the plant blooms, from
mid-September through November, the grass sends up a spike that has
seeds along it. Seeds are sticky and can stick to clothes, boots,
Another invasive grass known to be in many Fairfax County parks
looks similar to wavyleaf basketgrass but is taller, grows more
upright and prefers full sun (wavyleaf basketgrass prefers shade).
This invasive is small carpetgrass (Arthraxon hispidus).
Marsh dayflower/ Wart removing herb (Murdannia
Marsh dayflower (wartremoving herb) is an annual plant that invades
wetlands in the southeastern and northwestern United States. Plant
stems are not woody and appear fat because they retain water. They
will have a "juicy" look to them like a green bean. The plant
grows close to the ground. In August to November, small, pink,
three-petaled flowers appear. They occur singly or in small clusters.
The flowers are so small you may not notice them at first. Marsh
dayflower invades water edges and marshes and can grow above or below
Linden viburnum (Viburnum
Leaves are opposite from each other, slightly toothed, dark green
and often shiny. Leaf shape is highly variable from nearly round to
long and narrow on the same plant. Leaves are two to five inches long
and one to 2.5 inches wide. Leaves and young stems are usually
covered in soft hairs. Leaves drop relatively late in the fall. Fruit
turns bright red in September and October and will persist until
December. Two circular, dark spots at the base of the stem usually
can be seen on the underside of the leaf.
Yellow archangel (Lamiastrum galeobdolon)
Yellow archangel is a fast-growing, perennial ground cover that may
be either like a vine along the forest floor or upright depending on
conditions. Leaves are typically multi-colored with silvery-grey
markings, oval-shaped, hairy and serrated like a knife. Stems are
square, and leaves grow directly across from one another. Flowers are
small, yellow and tubular. They grow in pairs of clusters close to
stems and between leaves on flowering stems that are one to two feet
tall. The plant has a distinctive, unpleasant odor.
Giant hogweed (Heracleum mantegazzianum)
THIS SPECIES IS TOXIC AND SHOULD NOT BE TOUCHED. IF SEEN, REPORT
Leaves are deeply indented, serrated and up to five feet across.
There are numerous small white flowers in June or July clustered into
a flat-topped flower stalk up to 2.5 feet wide. The stems are hollow,
ridged, two to four inches in diameter and eight to 14-feet tall with
purple blotches and coarse white hairs. The hairs are especially
prominent at the point where the stem and the leaf stalks intercept.
The stems will have purple markings on them.
Kudzu (Pueraria lobata)
Kudzu is a rapidly growing vine. The vines have a "woody"
look to them and are covered in brown hairs. The large leaves are in
three leaflets. Typically, the two outside leaves resemble mittens
and the middle leaf has three lobes. However, the leaf shape is
highly variable and all three can be simple ovals. The flowers grow
individually and hang down from the stem. Flowers are about one-half
inch long, purple or white, and sweet-smelling. Flowering occurs in
late summer and is soon followed by production of brown, hairy,
flattened, seed pods each of which contains three to 10 hard seeds.
Java Dropwart (Oenanthe javanica)
O. javanica is a popular vegetable eaten throughout its native
range, which includes China , India , Indonesia , Japan and other
East Asian countries. It's other common names include water dropwort,
Chinese celery, and water celery. It invades the edges of water
features and prefers wet soil. It can grow partially covered in
water. The stems are cylindrical and upright or ascending from a
creeping base. The leaves are arranged alternately along the stems
and they are serrated, like a knife. Small white flowers are
clustered together (like Queen Anne's Lace) and bloom in mid-summer.
Leatherleaf Mahonia (Mahonia Bealei)
Mahonia is an evergreen shrub that can grow up to 10 ft tall. Leaves
are pinnately compound (like a fern) and up to 18 in long with 9-13
leaflets that resemble large holly leaves. Flowering occurs in late
fall and early winter when fragrant, lemon-yellow flowers develop.
Fruits appear in the spring in the form of green berries, about a
half inch long, that turn bluish black with a grayish bloom. Fruits
hang in grapelike clusters.
Check out our calendar
to see what sites are convenient or are hosting workdays when you are
Contact us by
email, or call 703-324-8750
Wear sturdy shoes, gloves, long pants and long sleeves, and bring
some water. Tools are provided.
Enjoy the company of others who care about the environment while
learning about our local forests.