Flowers of Fall: Pennsylvania’s Asters
By Greg Podniesinski
As summer begins to wind down and Labor Day approaches, a group of Pennsylvania wildflowers come into prominence—the asters.
With over 35 species of native asters in the commonwealth, there is a species for nearly every habitat you can imagine (and many can be found in the Pennsylvania Wilds). Many are quite rare or restricted to unique habitats while others thrive in abandoned old fields and disturbed areas. Many of our native asters, especially the showy ones, are also available in nurseries and make excellent landscape plantings for fall displays (“go native!”). Native asters come in a variety of hues from deep blue to pink to white, and shades in between.
Several common species of aster that thrive on disturbance and are found in old fields, roadsides, and even abandoned industrial land include the calico aster (Symphyotrichum lateriflorum), New England aster (Symphyotrichum novae-angliae) and heath aster (Symphyotrichum pilosum).
Photo credit: Heath aster by Fritzflohrreynolds
Other asters prefer wet “feet” and occupy marshes and wet meadows and woods, such as purple-stemmed aster (Symphyotrichum puniceum), zig-zag aster (Symphyotrichum prenanthoides) and late purple aster (Symphyotrichum patens).
Photo credit for block below, from left: Purple-stemmed aster by USDA-NRCS Plants; Zig-zag aster by Fritzflohrreynolds and Late purple aster by Fritzflohrreynolds.
Pennsylvania also is home to several rare asters, often restricted to unique and limited habitats.
The aptly named serpentine aster (Symphyotrichum depauperatum), a Pa. threatened species, is only found in southeast Pennsylvania where ancient serpentine bedrock lies at or near the surface. The serpentine aster tolerates the unique chemistry of serpentine soils, which are typically rich in magnesium and heavy metals such as nickel and chromium. These soils are also shallow and susceptible to drought, so while not a very showy aster, the serpentine aster is a tough, remarkable survivor.
Photo credit: Serpentine aster by David Stang
The rough aster (Eurybia radula), a Pa. threatened species, is found in cool, acidic seeps, bogs, and swamps. While common across much of Canada, this species has become rare or threatened across much of its range in the United States, including Pennsylvania.
Photo credit: Rough aster by John Kunsman
One of our rarest asters is the bog aster, (Oclemena nemoralis), a Pa. endangered species, a northern species near its southern geographical limit in Pa. It prefers cool sphagnum bog habitats in the northern tier of the state.
Photo credit: Bog aster by Greg Podniesinski
As summer fades, keep a sharp eye out for one of our many asters as they bring a splash of late-season color to our diverse landscapes.
About the Author: Greg Podniesinski is chief of the Natural Heritage Section of the PA Department of Conservation and Natural Resources – Bureau of Forestry, as well as State Director of the PA Natural Heritage Program. Podniesinski has worked for the Bureau for the last six years, and a total of 10 years with DCNR. He has also spent 20 years working with the PA Natural Heritage Program. Podniesinski earned his B.S. in Biology from the University of Notre Dame, his M.S. in Zoology from the University Of Maine and his Ph.D. in Environmental Science from the SUNY College of Environmental Science and Forestry at Syracuse. He has a particular interest in plant community ecology, floodplains, fens, bogs, shale and serpentine barrens, and is especially fond of native orchids and serpentine barren plants. This article was originally published in DCNR’s “Forest Fridays” e-newsletter. Learn more about DCNR here.