Invasive Plants in Murrysville, PA

AUG 06   SEP 06   OCT 06   JAN 07  APR 07

Pirate tickets for August 29 and August 30.
 
2 pairs of excellent Pirate tickets will be raffled off on August 23 among all people who volunteer more than 40 hours in the Murrysville parks eradicating the invasive plants. For more information, call Pia
van de Venne, Volunteer Coordinator Parks at 724 733 2770

Britt Slattery, USFWS Garlic Mustard Alliaria petiolata Origin: Europe Background Garlic mustard was first recorded in the United States around 1868, from Long Island, New York, and was likely introduced by settlers for food and medicinal purposes. Distribution and Ecological Threat Garlic mustard ranges from eastern Canada, south to Georgia and as far west as Kansas and Nebraska. It occurs in a wide range of moist to dry habitats including roadsides, floodplains, and forest edges and interiors and does not tolerate highly acidic soils. Garlic mustard invades areas disturbed by human activities and appears to be aided by white-tailed deer that prefer to eat native wildflowers and leave garlic mustard untouched. Garlic mustard displaces many native spring wildflowers such as spring beauty (Claytonia virginica), wild ginger (Asarum canadense), bloodroot (Sanguinaria canadensis), Dutchman's breeches (Dicentra canadensis), toothworts (Dentaria species) and trilliums (Trillium species) that occur in the same habitat. It is also credited with the decline of the West Virginia white butterfly (Pieris virginiensis) because chemicals in garlic mustard appear to be toxic to the butterfly's eggs. Britt Slattery, USFWS Description and Biology Plant: a biennial herb in the mustard family (Brassicaceae); completes its life cycle within two years and dies back by the second June, when it is recognizable only by its dried fruiting stalks; flowering plants range from 1 to nearly 4 feet in height. Leaves: crushed leaves and stems have a garlic-like odor; first-year plants appear as a rosette of kidney-shaped leaves that stay green throughout the winter; in its second year, the plant forms a shoot which rapidly elongates and flowers in early spring. Flowers, fruits and seeds: clusters of small white flowers in the axils of leaves along the stem; each flower has four petals in the shape of a cross; fruits are slender, erect capsules that contain a row of shiny black seeds when mature. Spreads: a single plant can produce hundreds of seeds, which are scattered up to several yards from the parent plant. Look-alikes: toothworts (Dentaria species), sweet cicely (Osmorhiza claytonii), wild anise (Osmorhiza longistylis) and early saxifrage (Saxifraga virginiensis). Prevention and Control Because garlic mustard seeds can survive for five or more years in the soil, effective management of garlic mustard requires a long-term commitment. Hand removal of entire plants, including the roots, is effective for light, scattered infestations. Cutting flowering plants low to the ground in spring will prevent flowering and thus seed production. Careful hand removal and bagging of plants with mature fruits can be done from June through August. Several herbicides are also effective for its control. Researchers are investigating the potential for biological control of garlic mustard. Native Alternatives Once garlic mustard has been removed, re-establish native groundcovers such as: wild ginger (Asarum canadense) Britt Slattery, USFWS lady fern (Athyrium filix-femina) Kenneth J. Sytsma, UWI evergreen wood fern (Dryopteris marginalis or intermedia) Emmet J. Judziewicz, UWI foam flower (Tiarella cordifolia) Britt Slattery, USFWS creeping phlox (Phlox stolonifera) Britt Slattery, USFWS New York fern (Thelypteris noveboracensis) Britt Slattery, USFWS   James H. Miller James H. Miller Oriental Bittersweet Celastrus orbiculatus Origin: Eastern Asia, Korea, China and Japan Background Oriental bittersweet was introduced into the United States in the 1860s as an ornamental plant and it is still widely sold for landscaping despite its invasive qualities. It is often associated with old home sites, from which it has escaped into surrounding natural areas. Distribution and Ecological Threat Oriental bittersweet occurs from New York to North Carolina, westward to Illinois. It infests forest edges, open woodlands, fields, hedgerows, coastal areas, salt marsh edges and particularly disturbed lands. While often found in more open, sunny sites, its shade tolerance allows it to invade forested areas. Oriental bittersweet is an aggressive invader that threatens vegetation at all heights in forested and open areas. It grows over other vegetation, completely covering and killing other plants by preventing photosynthesis, by girdling, and by uprooting trees through excessive weight. In the Northeast, Oriental bittersweet appears to be displacing the native climbing bittersweet, Celastrus scandens, through competition and hybridization. James H. Miller Description and Biology Plant: a deciduous, woody, twining vine in the staff-tree family (Celastraceae), which sometimes occurs as a trailing shrub. Stems of older plants sometimes grow to four inches in diameter. Leaves: glossy, rounded, finely toothed and arranged alternately along the stem. Flowers, fruits and seeds: abundant clusters of small greenish flowers emerge from most leaf axils; globular, green to yellow fruits split open at maturity to reveal three red-orange, fleshy arils that surround the seeds; seeds germinate in late spring. Spreads: Oriental bittersweet spreads by seed, which is dispersed to new areas by many species of birds. People also spread seed widely when using the plant for wreaths and ornamental arrangements. It also expands vegetatively by stolons and rhizomes, and through root suckering (the ability to send shoots up from the roots). Look-alikes: This plant is easily confused with our native climbing bittersweet vine (Celastrus scandens), which flowers at the stem tips rather in the leaf axils, it is imperative that correct identification be made before controls are attempted. Prevention and Control Manual, mechanical and chemical methods can be employed to control bittersweet. Vines can be pulled out by the roots, cut repeatedly or treated with systemic herbicides. No biological controls are currently known for oriental bittersweet. Native Alternatives Note: Although our native bittersweet (Celastrus scandens) is an excellent alternative plant to use, many nurseries confuse it with the exotic invasive Oriental bittersweet. Be certain of the species you are buying or choose another plant. Other options include: passionflower (Passiflora incarnata) R. Harrison Wiegand trumpet creeper (Campsis radicans) Britt Slattery, USFWS pipevine (Aristolochia macrophylla) R. Harrison Wiegand trumpet honeysuckle (Lonicera sempervirens) Britt Slattery, USFWS

Internet resources - http://www.paflora.org/,
http://www.invasivespeciesinfo.gov/,
http://tncweeds.ucdavis.edu
For more information or if you need help with invasive plants, call Pia van de Venne at 724 733 2770