One of the major invasives that needs removing at this time is...
Japanese Stiltgrass
Microstegium vimineum (Trin.) A. Camus
Grass family (Poaceae)
Japan, Korea, China, Malaysia and India
Background
Japanese stiltgrass was introduced into the United States in Tennessee around 1919 and likely escaped as a result of its use as a packing material for porcelain.
Distribution and Habitat
Stiltgrass is currently established in 16 eastern states, from New York to Florida. It occurs on stream banks, river bluffs, floodplains, emergent and forested wetlands, moist woodlands, early successional fields, uplands, thickets, roadside ditches, and gas and power-line corridors. It can be found in full sun to deep shaded forest conditions and is associated with moist, rich soils that are acidic, neutral or basic and high in nitrogen.
Ecological Threat
Stiltgrass threatens native understory vegetation in full sun to deep shade. It readily invades disturbed shaded areas, like floodplains that are prone to natural scouring, and areas subject to mowing, tilling and other soil-disturbing activities including white-tailed deer traffic. It spreads opportunistically following disturbance to form dense patches, displacing native wetland and forest vegetation as the patch expands.
Description and Biology
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Plant: annual grass resembling a small, delicate bamboo; mature plants grow to 2-3 ft. in height.
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Leaves: pale green, lance-shaped, asymmetrical, about 3 in. in length, with a shiny midrib.
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Flowers, fruits and seeds: hidden (cleistogamous), self-fertilizing flowers in axils and/or exposed (chasmogamous) flowers in terminal racemes of paired, hairy spikelets that open and are wind-pollinated; fruits awned and bristly; late summer to fall.
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Spreads: by seed and vegetative spread by rooting at joints along the stem—a new plant can emerge from each node; a single plant can produce 100-1,000 seeds that remain viable in the soil for at least three years, ensuring its persistence; seed germinates readily following soil disturbance. Although dispersal is not fully understood, seeds can be transported by water (e.g., surface runoff, streams, and floodwaters), in soil and gravel, in nursery grown plants, and on the feet of animals including humans.
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Look-alikes: Virginia cutgrass (Leersia virginica), hairy jointgrass or small carpetgrass (Arthraxon hispidus), and possibly other delicate grasses and wildflowers like Pennsylvania knotweed (Polygonum persicaria).
James H. Miller, USDA FS |
Prevention and Control
Because it is similar in appearance to several native grasses, it is important to know how to recognize and differentiate stiltgrass from look-alikes. Look for asymmetrical leaves with a shiny midrib and the stilt-like growth form. Attention to new infestations should be a priority. Because it is shallow-rooted, stiltgrass may be pulled by hand at any time. If flowering, cut plants back using a mower, weed whip or other device to prevent seed production. For extensive infestations, herbicides are the most practical and effective method currently (see Control Options).
Native Alternatives
Following disturbance to an area susceptible to stiltgrass, stabilize with native vegetation suitable to site conditions.
