Pennsylvania State-listed Noxious Weeds 14 records returned. Invasive.org is a joint project of University of Georgia - Center for Invasive Species and Ecosystem Health, USDA Animal and Plant Health Inspection Service, USDA Forest Service, USDA Identification Technology Program, and USDA National Institute of Food and Agriculture Introduced, Invasive, and Noxious Plants NRCS Invasive Species Policy Invasive Species Executive Order 13112. Noxious and Invasive plants typically reproduce via seed, root, or shoot. Tree-of-heaven (Ailanthus altissima) is an invasive tree and noxious weed in PA. Pennsylvania has listed 13 plants as noxious weeds, meaning the state has identified these plants as harmful to humans, agriculture, animals … Ocreae: Pair of stipules joined in a tubular sheath around the stem. Click on an accepted name below to view its PLANTS Profile with more information, and web links if available. A full list of noxious weeds in Pennsylvania can be found here . Noxious Weed: A plant determined by Pennsylvania law to be injurious to public health, crops, livestock, agricultural land or other property. This article displays images to assist with identification and provides recommendations for control, including a management calendar and treatment and timing table. Among the many threats to Pennsylvania’s native plants and animals, invasive species are major players. Noxious plant species are fewer in number than invasive plants as a whole, but each poses a greater threat. An invasive species is an organism that is introduced to an area outside its native range and causes or has the potential to cause harm to the environment, economy or human health.