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What is EDRR?

  Early Detection and Rapid Response  


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 undulatifolius)
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, etc.

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).

wavyleaf basketgrass   wavyleaf basketgrass

Marsh dayflower/ Wart removing herb (Murdannia keisak)
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 water.

Aneilema keisak    Aneilema keisak

Linden viburnum (Viburnum dilatatum)
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.

Viburnum  Viburnum

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.

Yellow Archangel  Yellow Archangel

Giant hogweed (Heracleum mantegazzianum)
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.

Woman standing next to Giant Hogweed

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.

Kudzu   Kudzu

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.

Java Dropwart  Java Dropwart

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.

leatherleaf mahonia, Mahonia bealei (Ranunculales: Berberidaceae)                           Leatherleaf

EDD maps

Check out our calendar to see what sites are convenient or are hosting workdays when you are available.

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.


Contact Fairfax County: Phone, Email or Twitter | Main Address: 12000 Government Center Parkway, Fairfax, VA 22035
Technical Questions: Web Administrator

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