Flora of the Spring Creek Canyon Trail
Take a walk during any season along the 4.4-mile trail winding its way along Spring Creek Canyon and you’ll be rewarded with a dizzying array of plants. Known locally as a botanical “hot spot” by amateur and seasoned botanists alike, Spring Creek Canyon boasts a mixture of mature forests and successional communities, cultivated areas and unique ecological communities each contributing to the botanical richness of the area. Although proximity to developed areas has overwhelmingly shaped the flora of Spring Creek, primarily through the invasion and spread of non-native plant species, native plant communities remain intact in many areas of the canyon, giving the intrepid visitor an authentic experience of riparian habitats in Central Pennsylvania.
The Spring Creek Canyon trail is more aptly characterized as a broad gravel path that follows Spring Creek. At the Fisherman’s Paradise trailhead, the path hews closely to the creek’s edge, separated only by a steeply sloped swath of riparian habitat. In this section, the tree canopy is dense, providing abundant shade from a mixture of sycamore (Platanus occidentalis), tulip poplar (Liriodendron tulipifera), basswood (Tilia americana), black willow (Salix nigra), black cherry (Prunus serotina), red maple (Acer rubrum), box elder (Acer negundo), flowering dogwood (Cornus florida), white pine (Pinus strobus), and black walnut (Juglans nigra) – the fruits of which litter the path in late summer.
The understory is dominated by shade-loving plants common in Pennsylvania forests including rattlesnake root (Prenanthes alba), Christmas fern (Polystichum acrosticoides), and wild geranium (Geranium maculatum). Crowded stands of scouring rush (Equisetum hyemale), one of our oldest living plants, although much reduced in stature from its tree-sized ancestors, occur in spots along the trail’s edge. The pencil-straight stems of this ancient plant, dark green and rough to the touch due to the presence of silica, were used in colonial times to scour pots and pans.
Photo 1 (left): Rattlesnake root (Prenanthes alba) photo credit: S. Chamberlain
The upslope side of the trail in this area of the canyon presents perhaps the best example of mature forest within the riparian corridor of Spring Creek. Many of the same species that occur adjacent to the creek also are found in upland forests where they mix with plants indicative of high-quality habitat. Here the canopy also includes Eastern hemlock (Tsuga canadensis), a denizen of Penn’s Woods and the state tree of Pennsylvania. Hemlock trees in central Pennsylvania have been hit hard by the woolly adelgid in recent years, a non-native insect pest introduced to the Commonwealth in the 1960s, and much effort has been expended to save remaining trees.
Hikers who explore this part of the trail in spring should keep an eye out for early-blooming “spring ephemerals” including toothwort (Dentaria laciniata), red trillium (Trillium erectum), rue anemone (Thalictrum thalictroides), early meadow rue (Thalictrum dioicum), Virginia saxifrage (Micranthes virginiensis), mayapple (Podophyllum peltatum), miterwort (Mitella diphylla), and bloodroot (Sanguinaria canadensis) - easily recognizable by its reddish stems and oddly-lobed leaves – that emerge with the first suggestion of warm weather and are sure to reward those who dare venture out in potentially frigid temperatures.
Photo 2: Bloodroot (Sanguinaria canadensis) photo credit: Wikimedia Commons
As spring fades into summer, these plants are soon eclipsed by a myriad of woodland wildflowers, ferns, and grasses such as Solomon's seal (Polygonatum pubescens), Jacob's ladder (Polymonium reptans), black cohosh (Actaea racemosa), horsebalm (Collinsonia canadensis), white wood aster (Eurybia divaricata), hayscented fern (Dennstaedtia punctilobula), white grass (Leersia virginica), mountain ricegrass (Piptatherum racemosum), false Solomon’s seal (Maianthemum racemosum) and wild ginger (Asarum caudatum). Although tempting, passersby entertaining the idea to take wild ginger root home to spice up their next meal would do well to resist the urge. Though once used by Native Americans as a seasoning, our wild ginger - fully unrelated to the culinary variety (Zingiber officinale) - has been shown to have carcinogenic properties.
Photo 3: Wild ginger (Asarum caudatum) photo credit: Walter Siegmund
Continuing down the path, steep cliffs arise along the left side of the trail. The rock faces of these towering megaliths support several plants that thrive in calcareous (limestone) soils. Common cliff-dwelling species observed include wild columbine (Aquilegia canadensis), early meadow rue (Thalictrum dioicum), and rock polypody (Polypodium virginianum).
Photo 4: Brown-eyed Susan (Rudbeckia triloba) with field crescent butterfly (Phyciodes pulchella) photo credit: S. Chamberlain
Upstream of the cliffs, the floodplain broadens and the canopy opens giving way to an assortment of both sun and shade-loving plants. While the overstory trees are familiar - black walnut, basswood, black cherry, white pine, tulip poplar, and red maple - the understory offers up a new bouquet of plants to explore. To the left, dense stands of flowering raspberry (Rubus odoratus) are visible along with wood nettle (Laportea canadensis), bottlebrush grass (Elymus hystrix), wild rye† (Elymus canadensis), smooth brome† (Bromus inermis), orchard grass† (Dactylis glomerata), reed canary grass (Phalaris arundinacea), chicory† (Cichorium intybus), burdock† (Arctium minus), brown-eyed Susan (Rudbeckia triloba), and dame’s rocket† (Hesperis matronalis). († indicates non-native plant) Many of these plants owe their place in our flora to the colonists who brought them here as livestock forage (smooth brome, orchard grass), for culinary purposes (chicory, the dried roots used as a substitute for coffee), or as garden favorites (dame’s rocket).
Further down the trail, carpenter’s square (Scrophularia marilandica) is a treat for keen eyes as is American spikenard (Aralia racemosa), it’s branches laden with reddish-purple berries in late summer. Other plants found along this section of the trail include alternate leaved dogwood (Cornus alternifolia), maidenhair fern (Adiantum pedatum) and two non-native invaders - Japanese stiltgrass† (Microstegium vimineum) and Japanese knotweed† (Fallopia sp.). The former is the scourge of many Pennsylvania forests, spreading via copious seed along trails and other areas of disturbance. The latter can form dense stands along streams. Once established, both are tough to eliminate and readily outcompete our native flora.
Photo 5 (left): Japanese knotweed (Fallopia sp.) photo credit: S. Chamberlain
Continuing upstream, the trail winds past a modern shooting range to the left and the old axe grinding mill of Mann Axe Works to the right, providing a glimpse into the past when the area was used to produce axes. Another bend in the river reveals relic fish hatchery ponds on the right side of the trail. A few ponds still store enough moisture to provide refuge for a variety of wetland plants including slippery elm (Ulmus rubra), narrow-leaved cattail (Typha angustifolia), monkey flower (Mimulus ringens), soft-stemmed bulrush (Schoenoplectus tabernaemontani), green bulrush (Scirpus atrovirens), great willow herb (Epilobium hirsutum) and soft rush (Juncus effusus).
From the fish ponds to Benner Spring, the canopy is more open and includes non-native trees such as tree-of-heaven† (Ailanthus altissima) and European alder† (Alnus glutinosa). Understory shrubs also are largely non-native, invasive species common to riparian habitats including privet† (Ligustrum spp.), multiflora rose† (Rosa multiflora), amur honeysuckle† (Lonicera mackii), Morrow’s honeysuckle† (Lonicera morrowii), burning bush† (Euonymus alatus) and autumn olive† (Elaeagnus umbellata). Vines clamoring among the vegetation include native liannas such as hog peanut (Amphicarpaea bracteata), poison ivy (Toxicodendron radicans), and Virginia creeper (Parthenocissus quinquefolia), as well as the highly invasive oriental bittersweet† (Celastrus orbiculatus).
Photo 6: Poison ivy (Toxicodendron radicans) photo credit: Wikimedia Commons
The herbaceous layer also comprises non-native plants such as garlic mustard† (Alliaria petiolata), lady’s thumb† (Persicaria maculosa), and dame’s rocket, which along with the shrub layer hide myriad botanical gems. One need only look closely to discover such treasures as wild geranium, nodding onion (Allium cernuum) and the more diminutive wild ginger whose crimson flowers peak out furtively beneath heart-shaped foliage.
Wetland plants also thrive in this area and are represented by the more common jewelweed (Impatiens capensis), its larger cousin pale jewelweed (Impatiens pallida), clearweed (Pilea pumila), white grass (Leersia virginica), and boneset (Eupatorium perfoliatum), as well as the somewhat elusive yet stunning blue lobelia (Lobelia siphilitica). The cheerful flowers of this showy native plant belie its morose botanical moniker, a nod to its historic use as a treatment for syphilis.
Photo 7: Blue lobelia (Lobelia siphilitica) photo credit: S. Chamberlain
Old field habitats are present in this section of the trail as well and provide excellent pollinator habitat. Common plants found in these areas include bee balm (Monarda fistulosa), green-headed cone flower (Rudbeckia laciniata), evening primrose (Oenothera biennis), purple coneflower (Echinacea purpurea) and goldenrods (Solidago spp.). These spaces along the trail offer the perfect opportunity to take a break, grab some water and snack, watch the bees and butterflies, and reminisce about all the wonderful plants you’ve encountered along the way.
While the Spring Creek Canyon trail ends at Rock Road, your exploration of plants in the Spring Creek watershed doesn’t have to! Check out these field guides to enhance your botanical experience in Central Pennsylvania:
Rhoads, A.F. and Block, T.A. 2017. Plants of Pennsylvania. University of Pennsylvania Press, Philadelphia, PA. 1056 pp.
Rhoads A.F. and Block, T.A. 2004. Trees of Pennsylvania. University of Pennsylvania Press, Philadelphia PA. 416 pp.
Newcomb, L. 1989. Newcomb’s Wildflower Guide. Little, Brown and Co. New York, NY. 490 pp.
Hallowell, A.C. and B.G. Hallowell. 2001. Fern Finder. Nature Study Guild Publishers. Rochester, NY. 59 pp.
Chamberlain, S.J. 2018. Field Guide to Grasses of the Mid-Atlantic. Penn State Press, University Park, PA. 167 pp.
† indicates non-native plant. Native plants are generally considered to be those found in Pennsylvania prior to European colonization.
Sarah Chamberlain is an Associate Research Professor at Penn State University and the curator of the Penn State (PAC) Herbarium. While her plant expertise is broad, she is especially fond of riparian and wetland plants, particularly grasses, sedges and rushes.