Within the undeveloped natural areas throughout Pennsylvania are its abundant native plant species. From groundcovers to tall, towering trees, Pennsylvania has over 2000 native plants. Valued for their stabilization of the environment---an effect overlooked and taken for granted for many years---native plants improve air quality, provide homes for native animals, have minimal demands and effects on soil quality and give the land its timeless scenic beauty.
A perennial flowering member of the Asclepiadaceae or milkweed family, butterfly weed (Asclepias tuberosa) grows in Pennsylvania, most of the United States excluding the northwestern states, and Ontario and Quebec in Canada. It grows to 3 feet tall and produces its orange or yellow flowers in midsummer. Its native soil is usually slightly moist to dry, and it thrives in full sun exposure.
Common Evening Primrose
A biennial flowering herbaceous forb member of the Onagraceae or willowherb family, common evening primrose (Oenothera biennis) produces yellow fragrant flowers that bloom from midsummer through the fall. Its flowers open in the evening and remain slightly closed during the daytime. Common evening primrose grows a single stem with its flowers forming at the top. The plant reaches 5 feet tall and grows in full sun and well-drained soil.
The flowering inflorescence (cluster of flowers) of this perennial herb member of the Liliaceae or lily family grows over 3 feet tall. Clusters of white, bell-like flowers form at the plant's top, blooming only for a short time in midsummer. White colicroot (Aletris farinosa L.) prefers dry sandy soil and full sun to partial shade exposure. It is native to Pennsylvania and most of the eastern half of the North America, and its other names include white stargrass and unicorn root.
Native to Pennsylvania, the northern part of North America, Alabama and Idaho, fool's parsley (Aethusa cynapium L.) is considered a hazardous annual plant. A member of the Apiaceae or parsley or carrot family, its foliage greatly resembles a cross between these two plants. Its white flower clusters that resemble yarrow blossoms bloom in mid to late summer, and the plant grows to less than 4 feet tall in moist to dry soil of varying types and thrives in full shade to full sun.
A small flowering perennial herb of the Asteraceae or aster family, bog aster (Oclemena nemoralis) grows to 2 feet in height in bogs or wet areas and in full sun exposure. Bog aster is native to Pennsylvania, south to Maryland and north to Labrador in Canada. The Connecticut Botanical Society reports that bog aster has an endangered status in their state. It produces white, purple-tinged daisy-like flowers with yellow centers. The plant is also commonly known as wood aster.