Invasive Plants PresentationJohn Ndiritu

Rapidan River Watershed

Ailanthus altissima Tree-of-heaven

Alliaria petiolata Garlic mustard

Ampelopsis brevipedunculata Porcelain-berry

Celastrus orbiculata Oriental bittersweet

Centaurea biebersteinii Spotted knapweed

Lespedeza cuneata Chinese lespedeza

Lythrum salicaria Purple loosestrife

Lonicera japonica Japanese honeysuckle

Pueraria montana Kudzu vine

Rubus phoenicolasius Wineberry

Rosa multiflora Multiflora rose

Polygonum perfoliatum Mile-a-minute

Myriophyllum aquaticum Parrot feather

Hedera helix English Ivy

Ailanthus altissima, Tree-of-heavenAppears as single trees in the residential subdivisions and watershed landscape.

Description from http://dendro.cnre.vt.edu/dendrology/syllabus/factsheet.cfm?ID=34

Leaf: Alternate, pinnately compound, 1 to 3 feet long, with 11 to 41 leaflets, leaflets are 2 to 6 inches long, pointed at the tip with large, glandular teeth near the base, green above and below.

Flower: Species is deciduous; small yellow-green, in long (6 to 12 inches) clusters, males have a disagreeable odor, appearing in late spring to early summer.

Fruit: An oblong, twisted samara, 1 to 1 1/2 inches long with the seed in the center, hanging in long clusters, ripens in late summer and disperse through the winter.

Twig: Stout, yellow to red-brown, with fine velvety hairs when young, easily broken with a large reddish brown pith; buds are relatively small and half-spherical sitting above large, heart-shaped leaf scars; terminal bud is absent. Strong odor (some are reminded of peanut butter) when broken.

Bark: Thin, light brown to gray, resembles the skin of a cantaloupe when young, later turning darker gray and rough. 

Form: A short to medium sized tree to 70 feet with heavy, open branches. Lower branches on larger trees tend to droop. Often grows in clumps

Alliaria petiolate, Garlic mustard

Distribution: Found in moist to dry habitats, flood plains and along roads. Tolerant to acid soils and assisted to spread when white tailed deer eat the native wildflowers.

Ecological Threat: Displaces native spring wildflowers and the garlic chemical poisons larvae of native butterflies and fungi associated with native trees

Plant: biennial herb in the mustard family (Brassicaceae); dried fruiting stalks may persist for many months.Leaves: crushed leaves and stems smell like garlic; first-year leaves are kidney-shaped, second year plants are heart-shaped with toothed margins and pointed tips.Spreads: a single plant can produce hundreds of seeds, most of which fall nearby but may be carried further by wind, water, wildlife and people.Look-alikes: toothworts (Cardamine or Dentaria), sweet cicely (Osmorhiza claytonii), wild anise (Osmorhiza longistylis) and early saxifrage (Saxifraga virginiensis)

Description from http://www.nps.gov/plants/alien/pubs/midatlantic/alpe.htm

Ampelopsis brevipedunculata, Porcelain-berryDistribution: Has spread in landscape from Massachusetts to Virginia. Grows in moist soils especially along forest edges, pond margins, stream banks in full to partial sunlight. Less tolerant to heavy shade and permanent wetness. Survives well after natural disturbances

Ecological Threat: Vigorous growth in open and wooded spaces and shades out native plants. Climbs and blankets native plants killing them.

Plant: deciduous, woody, perennial vine that resembles grape and climbs by non-adhesive tendrils at the base of each leaf; grows to 15-20 ft.

Leaves: alternate, simple, 3-5 lobed to highly dissected with heart-shaped base and coarsely toothed margins, shiny underneath with hairs on veins.

Flowers, fruits and seeds: tiny, greenish-white flowers with petals separate at their tips occur in flat-topped clusters opposite the leaves; appear in summer (June through August); fruit is a speckled berry in colors ranging from aqua to pink to purple; each berry carries 2-4 seeds.

Spreads: by seed that is eaten by birds and other small animals and dispersed in their droppings.

Look-alikes: native species of grape (Vitis) and peppervine (Ampelopsis) including heartleaf peppervine (Ampelopsis cordata) which is native to the Southeast and has unlobed leaves and smooth (hairless) stems; other native Ampelopsis have compound leaves

Description from http://www.nps.gov/plants/alien/pubs/midatlantic/alpe.htm

Celastrus orbiculata, Oriental bittersweet

Distribution: Slowly spread to 33 states. By 2011, it was widespread in the Northeast and sporadic but locally dominant can now be found farther south.

Habitat: Abudant in mesic, mixed hardwood forests and forest edges. Closely associated with yellow poplar and less in pine, oak and maple forests. More abundant at the headwaters of the watershed.

Ecological Threat: Vigorous growth in wooded spaces and uses woody shrubs and/or trees for structural support, intertwining its branches around support trunks and branches. Branches may eventually overtop or shade out native plants killing them.

Plant: deciduous, woody, perennial vine that can climb and/or sprawls up to 66 ft.

Leaves: leaves are alternate, oblong, 2 to 5 inches (4-12 cm) long.

Flowers, fruits and seeds: A typical plant bears upwards of 370 fruits/year

Spreads: Oriental bittersweet sprouts from roots, root fragments, and the root crown.

Description from http://www.fs.fed.us/database/feis/plants/vine/celorb/all.html#Introductory

Centaurea biebersteinii, Spotted knapweed

Distribution: Found in every state in the U.S. except Alaska, Georgia, Mississippi, Oklahoma, and Texas.. Abundant in the watershed landscape especially where precipitation ranges from 8-80 inches annualy. Survives in well-drained soils, open pine, fir and maple forests and rangelands. Develops deep roota that can reach water in water-stress periods.

Ecological Threat: Dominates natural and semi-natural habitats including barrens, fields, forests, prairies, meadows, pastures, and rangelands. Outcompetes native plant species, reduces native plant and animal biodiversity, and decreases forage production for livestock and wildlife; degrades soil and water resources by increasing erosion, surface runoff, and stream sedimentation. It has increased at an estimated rate of 27% per year since 1920.

Plant: Can live 3-7 years with reproduction by seed. Seeds remain viable for 5-8 years after dispersal normally by animals and humans activities.

Flowers: Purple to pink, 25-35 per head; blooms june to October. Heads are oblong or oval and found lone or in clusters

Spreads: Seeds dispersed and faster sprouting after natural disturbances.

Description from http://www.nps.gov/plants/alien/fact/cest1.htm

Lespedeza cuneate, Chinese lespedeza

Distribution and Habitat: Found in landscapes of the eastern U.S.; in fields, floodplains, pond borders, stream banks, swamps, meadows, open woodlands, roadsides and other disturbed grounds. Found in sunny habitat and less in shaded areas such as forest with thick canopies.

Ecological Threat: An invasive plant that threaten native species in open areas of the meadows, prairies, open woodlands, wetland borders and fields. Grows rapidly and displaces native plants, forming extensive monocultures with extensive seed bank in the soil. The seeds have long residence while the plant itself is not good as forage for livestock and wildlife.

Plant: warm season, perennial herbaceous plant with an erect growth form, 3-5½ feet in height; mature stems are somewhat woody and fibrous with sharp, stiff, flattened bristles.

Leaves: each leaf is divided into three smaller leaflets which are narrowly oblong and pointed, with awl-shaped spines and wedge-shaped bases; leaflets are covered with densely flattened hairs, giving a grayish-green or silvery appearance.

Flowers, fruits and seeds: flowers small (about ¼ in.) creamy white to pale yellow with central purple spots, single or in clusters of 2-4 in axils of upper and median leaves, summer; fruits form in fall; seeds tiny, bean-shaped, yellow to light brown.

Spreads: by seed that is consumed by animals such as bobwhite quail and passed through digestive tract and deposited in new locations.

Look-alikes: other species of Lespedeza including native and non-native species.

Description from http://www.nps.gov/plants/alien/fact/cest1.htm

Lythrum salicaria, Purple loosestrife

Distribution and Habitat: Found in every state except Florida. This plant species has invaded wetlands, wet freshwater meadows, tidal and non-tidal marshes, river and stream banks, pond edges, reservoirs and ditches. In the Rapid River watershed mostly along road divides, plant plots and lawns.

Ecological Threat: Grows fast and establishes itself replacing native vegetation with a dense, homogeneous stand that reduces local biodiversity, endangers rare species and provides little value to wildlife. Plant: erect perennial herb with a square, woody stem

usually covered by downy hair; 4-10 ft. high, depending upon conditions.

Leaves: lance-shaped, stalk-less and rounded to heart-shaped at the base; arranged in pairs or whorls around the stem.

Flowers, fruits and seeds: Has magenta-colored flower spikes throughout much of the summer. Individual flowers have five to seven petals. A single mature plant can have 30-50 stems arising from one rootstock, and can produce an estimated two to three million seeds per year. The flowering season can go from June to September; flowers pollination by insects attracted to it by abundant supply of nectar.

Spreads: Produces vast quantities of seeds, dispersed by wind and water. Readily reproduces vegetatively through underground stems at a rate of about one foot per year.

Look-alikes: from a distance, purple loosestrife may be confused with blue vervain (Verbena hastata), blazing star (Liatris aspera and L. spicata), Canada germander (Teucrium canadense), swamp milkweed (Asclepias incarnata), and fireweed (Chamaenerion angustifolium).

Description from http://www.nps.gov/plants/alien/pubs/midatlantic/lysa.htm

Lonicera japonica, Japanese honeysuckle

Distribution and habitat: Introduced from Japan in the 1800’s as an ornamental plant, for erosion control, and for wildlife forage and cover. Its highly fragrant flowers provide a tiny drop of honey-flavored nectar enjoyed by children. Found in many regions that do not have severe winter temperatures. Inhabits fields, forests, wetlands, barrens, and disturbed lands.

Ecological Threat: This invasive has as few natural enemies allowing it to spread widely and out-compete native plant species. Its evergreen to semi-evergreen hence has added growth advantage over winter stresses native species. Kills especially shrubs and young trees by girdling when vines twist tightly around stems and trunks, cutting off the flow of water through the plant. Also covers the vegetation cutting-off sunlight from reaching native plant species and spreads quickly through rapid rooting in the soils.

Growth and spread: Through vegetative (plant growth) and sexual (seed) means. Produces long vegetative runners that develop roots where stem and leaf junctions (nodes) come in contact with moist soil. Underground stems (rhizomes) help to establish and spread the plant locally. Long distance dispersal is by birds and other wildlife

Description from http://www.nps.gov/plants/alien/fact/loja1.htm

Pueraria montana, Kudzu vineDistribution and Habitat: Predominantly found in the eastern U.S., but spreading to other landscapes. In the Rapidan River watershed found along the riparian areas. Grows in wide range of conditions and soil types with habitats preferred habitats being open, sunny areas like forest edges, abandoned fields, roadsides and disturbed areas. Grows best in mild winter regions with about 40 inches precipitation.

Ecological Threat: Rapid and expansive growth (much as 1 foot a day) covering the native plant species denying then sunlight. Kill trees through girdling and the extra weight of vines can lead to toppling during storms.

Plant: climbing perennial vine in the pea family (Fabaceae)Leaves: alternate, deciduous, and compound, with three broad leaflets up to 4 in. across, leaflets may be entire or lobed with hairy margins.

Spreads: By vegetative means through runners & rhizomes and by vines that root at the nodes and also through see where resin bee serves as a pollinator.

Look-alikes: Thick tangles of various vines including grape, porcelainberry and bittersweet may be mistaken for kudzu as well as some native three-leaved vines in the pea family.

Description from http://www.nps.gov/plants/alien/pubs/midatlantic/pumol.htm

Rubus phoenicolasius, Wineberry

Distribution and Habitat: Found in the region from New England to North Carolina. Occurs along forest, field, stream and wetland edges and in open woods, preferring moist habitats. Has noticeable presence in patch areas of forested Rapidan River headwaters.

Ecological Threat: Forms dense cover and shady thickets that displacing native plants and altering habitat structure.

Plant: multi-stemmed shrub with spiny stems densely covered with reddish, glandular hairs, also on flowering stems and buds.

Leaves: alternate, divided into three leaflets with toothed margins, terminal leaflet largest; undersides conspicuously white.

Flowers, fruits and seeds: flowers with five white petals occur in springtime; bright red edible berries produced in early summer.

Spreads: Seed is consumed and dispersed by birds and mammals &humans and by vegetative means when new plants grow from the tips of canes that touch the ground and new plants sprout from root buds.

 

Description from: http://www.nps.gov/plants/alien/pubs/midatlantic/ruph.htm

Rosa multiflora, Multiflora roseDistribution and Habitat: Found in most of the eastern, Washington and Oregon. Can withstand wide range of soil, moisture and light conditions and is able to invade fields, forests, prairies, some wetlands and many other habitats.

Ecological Threat: Grows aggressively and produces large numbers of fruits (hips) that are eaten and dispersed by a variety of birds. Dense thickets cover native shrubs and herbs from establishing and may be detrimental to nesting of native birds.

Plant: multi-stemmed shrub, sometimes climbing vine, with arching stems and recurved thorns.

Leaves: divided into five to eleven sharply toothed leaflets; leaf stalks with fringed stipules (paired wing-like structures).

Flowers, fruits and seeds: clusters of showy, fragrant, white to pinkish, 1 in. wide flowers appear during May; small bright red fruits, or rose hips, develop during the summer and remain on the plant through the winter.

Spreads: Reproduces by seed and by forming new plants from the tips of arching canes that can root where they contact the ground. An average plant produces an estimated one million seeds per year, which remain viable in the soil for up to 20 years.

Look-alikes: Rasture rose (Rosa carolina); swamp rose (Rosa palustris); Allegheny blackberry (Rubus allegheniensis); flowering raspberry (Rubus odoratus). Only multiflora rose has the combination of upright arching stems and fringed stipules.

 

Description from: http://www.nps.gov/plants/alien/pubs/midatlantic/romu.htm

Polygonum perfoliatum, Mile-a-minute

Distribution and Habitat: Found in parts of Connecticut, Delaware, Massachusetts, Maryland, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Virginia, West Virginia, and Washington, DC. Establishes on stream banks, parks, open space, road shoulders, forest edges and fence lines.

Ecological Threat: Grows rapidly, covering shrubs and other vegetation, blockings sunlight and overwhelm them with the excessive weight causing distortion of stem and branches. Due to expansive nature, a threat to forest operations, nurseries and horticultural crops. Stems are armed with recurved barbs which are also present on the underside of the leaf blades

Leaves: Leaves are shaped like an equilateral (equal-sided) triangle and alternate along the narrow, delicate stems. Distinctive circular, cup-shaped leafy structures, called ocreae, surround the stem at nodes, thus the name ‘perfoliata.

Flowers, fruits and seeds: Flower buds, and later flowers and fruits, emerge from within the ocreae. The fruits are attractive, deep blue and arranged in clusters at terminals. Each berry-like fruit contains a single glossy, black or reddish-black hard seed called an achene

Spreads: primarily a self-pollinating plant. Vines generally die with the first frost. 

Description from: http://www.nps.gov/plants/alien/fact/pepe1.htm

Myriophyllum aquaticum, Parrot feather

Distribution and Habitat: Found in at least 26 states throughout the United States. It is limited to non-tidal, freshwater, slow-moving water bodies including tributaries, ponds, lakes and canals. It prefers good light, slightly alkaline and high-nutrient environments. Mostly in ponds, lakes and small streams in Rapidan River watershed.

Ecological Threat: Forms dense mats and compete with native aquatic plants, especially in shallow ponds. It also provides habitat for mosquito larvae, impedes boats and clogs drainage ditches.

Plant: aquatic plant with stout elongate stems suspended in the water column and/or floating; both stems and submerged leaves may be reddish tinted; gray-green tips of the stems with leaves may protrude above the water.

Leaves: well-developed, finely pinnately divided, in whorls of mostly five with smooth leaf margins.

Flowers, fruits and seeds: flowers and fruits, if present emerge from axils of leaves.

Spreads: vegetatively from whole plants or fragments; it can be dispersed by people dumping aquaria into rivers and ponds and by animals carrying fruits and fragments on their bodies.

Look-alikes: many species of submerged aquatic plants including non-native invasive Eurasian water-milfoil (Myriophyllum spicatum), and native species such as Northern water-milfoil (M. sibiricum), coontail (Ceratophyllum dmersum) and water marigold (Megalodonta beckii).

 

Description from: http://www.nps.gov/plants/alien/pubs/midatlantic/myaq.htm

 

Hedera helix, English Ivy

Distribution and Habitat: Common in lawns and landscape in the eastern U.S. Used in many residential subdivisions in the Rapidan River watershed as ground cover. Establishes under shady to full sun conditions in soils that are moderately fertile. Habitats invaded include forest openings and edges, fields, cliffs, steep slopes, and disturbed areas.

Ecological Threat; Aggressive invader on the ground and on trees, blocks sunlight and weighs heavy on vascular plants killing them. Is reservoir for bacterial leaf scorch (Xylella fastidiosa), a harmful plant pathogen that affects a wide variety of native and ornamental trees such as elms, oaks and maples.

• Plant: evergreen perennial climbing vine that attaches to bark of trees, brickwork and other surfaces by root-like structures that exude a glue-like substance to aid in adherence.

• Leaves: alternate, dark green, waxy, somewhat leathery; extremely variable leaf forms, from unlobed to 3-5 lobed; typically green with whitish veins.

• Flowers, fruits and seeds: flowering occurs in late summer to early fall, typically under full sun conditions; flowers are small, greenish-yellow and occur in globular starburst type inflorescences at tips of flowering stems; fruits are black with a fleshy outer layer and stone-like seeds.

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Description from: http://www.nps.gov/plants/alien/pubs/midatlantic/hehe.htm