Plants in mountainous regions usually require rocky soil and are able to grow at high elevations. The chief causes for the endangerment of mountain plants in Pennsylvania is road construction and deforestation via the timber industry and urbanization. Found in northwestern Pennsylvania, Canada buffaloberries are endangered since its required rocky soil and habitat is limited within the state. Maryland hawkweed, or Hieracium greenii, is found in south central Pennsylvania, located within the Appalachian Mountains. This plant is endangered in Pennsylvania since its primary habitat, shale barrens, is not prolific in the Keystone State. Other endangered plants in Pennsylvania's mountainous regions are Canby's mountain-lover, ebony sedge, tall larkspur and thick-leafed meadowrue.
Some of Pennsylvania's endangered plants live at the base of the state's forested regions, such as Allegheny National Forest and Susquehannock State Forest. When trees are cut down for timber or urbanization purposes, the population of the forest floor's flowering plants decline as a result. Common shooting stars, small whirled pogonias, variable sedge and white monkshood are endangered plants due to deforestation from the timber industry and agriculture. The yellow passionflower is a vining plant found in the wetlands of southwestern Pennsylvania and is endangered in Pennsylvania since the state is barely within the native range of this plant. Other plants who suffer this same fate in Pennsylvania are glade spurge, Mitchell's sedge and white-twisted stalk.
Prairie or grassland plants are not covered by trees; thus, they are able to receive full sunlight throughout the year. These types of plants also require little water for growth, unlike wetlands plants. However, two of Pennsylvania's prairie plants are on the brink of extinction: eared false-foxglove and hispid gromwell. The only place to find hipsid gromwell plants in Pennsylvania are the coastal plains near Lake Erie; beach erosion and the introduction of invasive plants are some of the reasons for this plant's endangerment. Eared false-foxgloves only live in eastern Pennsylvania and are endangered due to loss of habitat. These plants are also cut during the summer haying period.
Wetland plants are plant species that grow in or around bogs, marshes, swamps, lakes and river. These plants are often referred to as a wetland indicator species. The main causes for the endangerment of these plants are the creation of man-made lakes, water degradation and habitat fragmentation. Swamp pink, a pink-petaled plant, is endangered due to the creation of the Pymatuning Reservoir and is found in the northeastern and northwestern corners of Pennsylvania. As of April 2011, Jacob's ladder plants are only found in northeast Pennsylvania. The primary reasons for this plant's endangerment is collecting for gardens, habitat fragmentation and urbanization. Pennsylvania's endangered wetland plants also include the fall dropseed muhly grass, large-flowered marshallia, northeastern bulrush and spreading globeflower.