CHAPTER 13 Middle Schuylkill River Conservation Landscape

The confl uence of the Perkiomen Creek and the Schuylkill River is at the center of the Middle Schuylkill River Conservation Landscape. The landscape includes the riparian corridor along the Schuylkill River from Port Kennedy to just below Royersford. Floodplains and forested cliffs and ravines along the river are signifi cant natural features. Valley Forge National Histori- cal Park, the John James Audubon Center at Mill Grove, and the Oakes Reach of the Schuylkill Canal are important historical resources.

Description Location The Middle Schuylkill River Conservation Landscape occupies 6,451 acres including parts of Upper and Lower Providence and Upper Merion Townships and extends up the Perkio- men Creek to Yerkes. It adjoins the Skippack Creek Conservation Landscape and the Middle Perkiomen Creek Corridor (Figure 13.1). Core areas include Valley Forge National Historical Park and the John James Audubon Center at Mill Grove. Other publicly owned tracts include Lock 60 and the Oakes Reach of the Schuylkill Canal, Upper Schuylkill Valley Park, and Lower Perkiomen Valley Park. The Perkiomen Trail connects with the Schuylkill River Trail within this landscape. Another connection is with the Horseshoe Trail, which starts at Valley Forge National Historical Park and extends through Chester County to the west. The Montgomery County open space plan also envisions a trail along Skippack Creek connecting with Evansburg State Park.

Hydrology This landscape is entirely within the Schuylkill River drainage basin. It includes the mouth and lower reach of the Perkiomen Creek, as well as several small tributaries that enter the Schuylkill River on the northeast side. The Schuylkill and Perkiomen are designated as WWF MF (warm water fi shery, migratory fi shes). To the southwest, Valley Creek, the county’s only EV stream (exceptional value), which forms the border with Chester County, is the only signifi cant tributary. Fish ladders are in place at the Fairmount and Flat Rock Dams, and one is under construction at Norristown Dam. A fourth ladder is planned for Black Rock Dam in 2008. These fi sh ladders will further facilitate the upstream movement of migrating shad, which have already been de- tected after a gap of many years. Wetlands are present along the Perkiomen Creek on the Mill Grove site and in the fl oodplain of the Schuylkill River. Impoundment basins, created as part of the river cleanup in the late 1940s, are located along the Schuylkill in Valley Forge National Historical Park and just below Port Providence on the north side of the river.

Natural Areas Inventory Update 2007 207 208 Natural Areas Inventory Update 2007 Natural Areas Inventory Update 2007 209 210 Natural Areas Inventory Update 2007 Natural Areas Inventory Update 2007 211 Geology North and east of the Schuylkill River the geology consists of consecutive bands of Newark Basin Triassic sediments including Stockton Formation sandstones, shales and siltstones; Locka- tong argillites; and Brunswick shales from south to north respectively (Figure 13.2). Where the harder argillite intersects the Schuylkill in the vicinity of Mont Clare, the river forms a dramatic loop with steep cliffs and deeply etched side ravines that defi ne the river valley. The Stockton Formation extends on the southwest side of the river where the southern edge of the Newark basin meets a complex of much older rock including Wissahickon schist, Chickies quartzite, and Ledger and Conestoga Formation limestones in Valley Forge National Historical Park. Port Kennedy Cave, located in a lobe of the Ledger Formation limestone that extends to the river on the south side, is identifi ed as an important geological feature because of the unusual assemblage of Pleistocene era fossils found there. Originally exposed by limestone quarrying, the site was excavated between 1870 and the 1896 when water seeping in from the river forced a cessation of work. The cave produced a huge number of specimens including saber-toothed ti- ger, giant ground sloth, mastodon, giant cave bear, short-faced skunk, horse, tapir, mountain lion, coyote, wolverine, badger and black bear. The specimens are housed at the Academy of Natural Sciences of Philadelphia. In the early 20th century the site was fi lled in with asbestos-containing waste from the near- by magnesia manufacturing operation and the exact location became obscured. However a recent study of historical documents and local topography has resulted in re-establishing the precise location.

Forest Cover Forests cover 2,505 acres of this landscape, 39 percent of the total land area; of that total 1,023 acres qualifi es as interior forest and 78.8 acres is riparian forest (Figure 13.3).

Critical Features The Middle Schuylkill Conservation Landscape includes one priority site identifi ed in the 1995 Natural Areas Inventory: Mont Clare Cliffs and Ravines. PNHP-listed species confi rmed to be present in the landscape include redbelly turtle and two plants: toothcup and a species of dod- der (Cuscuta campestris). Extensive riparian habitat along the Schuylkill River and the Perkio- men Creek are critical to the diversity of species found in the landscape, especially reptiles and amphibians and birds. Birds – See data for Valley Forge National Historical Park below. Reptiles and Amphibians – See lists for Valley Forge National Historical Park and Mont Clare Cliffs and Ravines below.

Past Uses The industrial and transportation history of the Schuylkill River corridor is discussed in the

212 Natural Areas Inventory Update 2007 introduction to this report. The Oakes Reach and Lock 60, a preserved section of the Schuylkill Canal, lies along the east side of the river between Port Providence and Oakes. Several copper and lead mines were located in the vicinity of the village of Audubon as early as 1780. A lead mine at Mill Grove reportedly furnished bullets for the Continental Army. By the mid 1800s, both lead and copper were being mined at several additional mines located along Mine Run on both sides of Egypt Road. Valley Forge National Historical Park was the site of the Revolutionary Army encampment dur- ing the winter of 1777-1778.

Preservation Status and Other Designations The Schuylkill River National and State Heritage Area includes the Middle and Upper Schuylkill Conservation Landscapes as defi ned in this study. Designated by the state in 1995, the Heritage Area became a joint project of the National Park Service and the Pennsylvania Department of Conservation and Natural Resources in 2000. It is managed by the Schuylkill River Greenway Association. The Schuylkill is also des- ignated as a Pennsylvania Scenic River. Protected lands within the landscape include 3,452 acres of Valley Forge Historical National Park (1,964 acres in Montgomery County) and 427 addi- tional acres of county parklands (Fig- ure 13.4). Andruss Island, a 26.9-acre island in the Schuylkill River is owned by The Natural Lands Trust. Mill Grove, the home of John James Audubon, is listed on the National Reg- ister of Historic Places. The Schuylkill Trail in Valley Forge National Park

Core Areas Valley Forge National Historical Park At the time of the Revolutionary War encampment the landscape around the forge on Valley Creek was agricultural. Farms averaged 189 acres in size and were divided into small, fence- enclosed fi elds of 1 to 10 acres. Wheat was the main cash crop, but a variety of other grain and vegetable crops were also grown. To this day, fencerows in the park represent the property lines from the encampment era. Park management has attempted to represent the agrarian landscape of the late 1700s with meadows. When the Continental Army arrived, about one-third of the area was still forest-covered. Data from early deed descriptions (witness trees) indicate a forest dominated by white and black oak, and hickory with some chestnut. During the encampment nearly all of the trees were cut

Natural Areas Inventory Update 2007 213 for fuel or building material. Present day forested areas contain trees that have grown since the historical period. Plant Diversity – Several records of Pennsylva- nia Natural Heritage Program-listed plants exist for the park. A large population of toothcup is present in the impoundment basin on the north side of the Schuylkill River; a rare species of dodder is present at the same site. American holly grows on the slope below the chapel; tawny ironweed once grew on Mount Joy, although its current status is uncertain given the level of deer browse. A stand of possum-haw was present along Valley Creek, protected from deer by a fence. The meadows were thought to have included a population of a rare sedge Toothcup at Valley Forge National Historical Park (Carex gravida); but subsequent re-examination of the specimens deposited in the herbarium of the Academy of Natural Sciences of Philadelphia has revealed that they were misidentifi ed specimens of the more common Carex aggregata. Plant Communities – Classifi cation and mapping of vegetation types was carried out by The North Carolina State University Center for Earth Observation and the Pennsylvania Science Offi ce of the Nature Conservancy under a contract with the National Park Service in 2005. No regionally rare plant communities were found in the park; the single most common vegetation type was grassland at 32.3% of mapped area. Successional forest occupied 11.4% of the study area and tuliptree – oak forest 6.8%. Natural vegetation quality within the park was described as fair to poor due to heavy deer browse, which has created depauperate herb and shrub layers and eliminated forest regenera- tion. Successional forests and other areas that have been disturbed recently are also severely impacted by invasive, non-native species. See Table 13. 1 below for a list of vegetation types described for the park.

Table 13.1 - Plant Community Types of Valley Forge National Historical Park (Source: Podniesinski et al. 2005)

Chestnut oak – black birch talus slope Dry oak forest Tuliptree – oak forest Sycamore – green ash fl oodplain forest Silver maple fl oodplain forest Northeastern modifi ed successional forest Successional old fi eld/shrublands Grassland Wet meadow Skunk-cabbage seepage meadow Conifer plantation Broad-leaf tree plantation

214 Natural Areas Inventory Update 2007 Reptiles and Amphibians – Two recent surveys of the reptiles and amphibians of Valley Forge National Historical Park have documented a combined total of 31 species: 7 species of salaman- ders, 8 species of frogs and toads, 6 species of turtles, and 8 species of snakes. An inventory by Tiebout carried out from September 1999 - February 2002 for the National Park Service docu- mented 29 species. Twenty-four species were found in the park in a 2006-07 survey conducted by Marlin Corn for this study. The combined results of the 2 inventories are shown in Table 13.2.

Table 13.2 — Reptiles and Amphibians of Valley Forge National Historical Park (Source: surveys by Tiebout in 1999-2002 and Corn in 2006-2007)

1999 - 2002 2006 - 2007 Status Salamanders Northern redback salamander x x Northern red salamander x x Northern dusky salamander x x Red-spotted newt x x Longtail salamander x x Northern two-lined salamander x x Northern slimy salamander x x Frogs and Toads Gray treefrog x x Spring peeper x x Green frog x x Pickerel frog x x Wood frog x Bullfrog x x American toad x x Fowlers toad x Turtles Redbelly turtle x Pennsylvania threatened Red-eared slider x introduced Eastern painted turtle x x Eastern spiny softshell turtle x Map turtle x x Common snapping turtle x x Common musk turtle x x Eastern box turtle x Snakes Northern copperhead x x Northern black racer x x Northern brown snake x Northern ringneck snake x x Queen snake x Eastern garter snake x x Eastern milk snake x Northern water snake x x

Natural Areas Inventory Update 2007 215 Only the redbelly turtle is of offi cial conservation concern; it is classifi ed as threatened by the Pennsylvania Natural Heritage Program. Several other species are locally rare including red- spotted salamander, slimy salamander, wood frog, Fowler’s toad, common musk turtle, common map turtle, northern brown snake, and eastern milk snake. The only non-native species found is the red-eared slider. Tiebout identifi ed lowland forest and wetlands in the riparian corridor on the north side of the Schuylkill River as a hotspot of herpetofauna diversity within the park and recommended protecting these areas from unauthorized off-trail mountain biking Birds – A bird inventory of Valley Forge National Historical Park was conducted between May 1991 and May 2001. The authors reported a total of 153 species, 91 of which were present dur- ing the breeding season. An earlier inventory conducted during the 1984-1989 Breeding Bird Atlas Survey indicated 73 confi rmed or probable breeding species in the block centered in Valley Forge National Historical Park. A combined list from these two sources provides a total of 157 species including 23 with some level of conservation concern (Table 13.3 and Appendix 13.A).

Table 13.3 — Birds of Conservation Concern that are known from VFNHP (Source: Yahner et al. 2001)

American Black Duck Audubon watch list Black-throated Blue Warbler Audubon watch list Blue-winged Warbler USFS management concern Canada Warbler Audubon watch list Cerulean Warbler Audubon watch list, USFS management concern Chestnut-sided Warbler USFS management concern Common Snipe S3 (state vulnerable) Eastern Meadowlark USFS management concern Field Sparrow USFS management concern Grasshopper Sparrow USFS management concern Long-eared Owl S2 (state imperiled) Louisiana Waterthrush Audubon watch list, USFS management concern Marsh Wren S3/S4 (state imperiled/vulnerable) Northern Flicker USFS management concern Northern Harrier S3 (state vulnerable), USFS management concern Northern Saw-whet Owl S3 (state vulnerable) Osprey PA threatened Pied-bill Grebe S3 (state vulnerable) Red-headed Woodpecker USFS management concern Red-shouldered Hawk USFS management concern Veery USFS management concern Wood Thrush Audubon watch list, USFS management concern Worm-eating Warbler Audubon watch list, USFS management concern

216 Natural Areas Inventory Update 2007 Eastern Meadowlark, photo by Howard Eskin Deer Status – Deer overabundance has become a serious ecological problem in Valley Forge Na- tional Historical Park. A series of fenced and unfenced plots established on Mount Misery and Mount Joy in 1992 provide dramatic evidence of the loss of native species diversity and vegeta- tion structure except where deer are excluded. In addition regeneration of forest trees has been affected and cover by non-native invasive plants has increased. In 2006 park staff estimated that there were 244 deer per square mile in the park. Over browsing by deer has been so severe that the ability of scientists to classify forest types in the park was affected. Oak forest associations were especially diffi cult to classify due to the complete removal of native shrub and herbaceous vegetation. Over browsing has jeopardized several state-listed endangered and threatened plants in the park. Ginseng has disappeared from unfenced plots. One species, possum-haw, has been fenced to prevent its local extirpation. A draft deer management plan has been prepared and is now under discussion; public scoping meetings were held in November 2006. It has been determined that action to reduce the deer herd is needed; alternatives including lethal reduction, contraception, and fencing of targeted natural communities are being considered. Invasive Plants – Japanese stilt grass and wineberry are abundant in over-browsed woodlands throughout the park. The former silt basins and riparian forests contain infestations of numerous non-native invasive plants including common reed, Japanese knotweed, reed canary grass, Japa- nese stilt grass, lesser celandine, mile-a-minute weed, Japanese honeysuckle, Amur honeysuckle, multifl ora rose, obtuse-leaved privet, autumn olive, Norway maple, tree-of-heaven, Oriental bit- tersweet, ground ivy, stinging nettle, mugwort, and garlic mustard.

John James Audubon Center at Mill Grove Owned by Montgomery County since 1951, and now managed by the National Audubon Society as a nature preserve and museum, Mill Grove is on National Register of Historic Places. The 175-acre site is located on the south bank of the Perkiomen Creek about a mile above its confl u- ence with the Schuylkill River.

Natural Areas Inventory Update 2007 217 Past Uses – This site has been continuously occupied since the house was built in 1762. It was the home of John James Audubon in the early 1800s. At that time, in addition to a working farm, the property contained several mills and a lead mine. Lead and copper mining continued in the area into the mid 1800s. Plant Diversity – During a mid-April visit to the site 129 species of vascular plants were re- corded, 45 of which (35 percent) were non-native. This list, which is included in Appendix 13.B, is far from complete; additional visits would be necessary later in the growing season to compile a more complete inventory. Natural Communities – The extensive fl oodplain area along Perkiomen Creek and Mine Run contains typical sycamore – box-elder fl oodplain forest. The canopy and shrub layers are dominated by native species including sycamore, box-elder, white ash, American elm, black walnut, spicebush, and silky dogwood. Several non-native shrubs including Siebold vibur- num, obtuse-leafed privet, multifl ora rose, and Amur honeysuckle were also present. The herbaceous layer in this palustrine forest community was dominated by non-native, invasive species. In early spring the ground layer is yellow with the fl owers of lesser celandine, which is so dense that native wildfl owers such as trout lily, spring-beauty, mayapple, common blue violet, and false mermaid that bloom at the same time, were being crowded out. Other seri- ously invasive plants present on the fl oodplain included mile-a-minute weed, Japanese knot- weed, reed canary grass, common reed, ground-ivy, dame’s-rocket, and moneywort. A skunk- cabbage dominated wetland community was present in what may be an old stream channel at the base of the slope. Steep, west-facing forested slopes adja- cent to the fl oodplain contain a red oak – mixed hardwood forest community on the lower to mid slopes grading to dry oak - heath forest on the upper slopes. Canopy trees include red oak, American beech, white oak, tuliptree, red maple, sugar maple, wild black cherry, and a few Canada hemlocks. On the drier up- per slopes, black oak, chestnut oak, and Lesser celandine on the floodplain of the Perkiomen creek at black birch are more prominent. The Mill Grove sparse shrub layeris dominated by witch- hazel; maple leaf viburnum is also present in a few spots. Small remnants of mountain laurel and lowbush blueberry remain on the upper slopes. Native herbaceous species include early saxi- frage, woodrush, white wood aster, sessile-leaved bellwort, early meadow-rue, Solomon’s-seal, false Solomon’s-seal, mayapple, marginal wood fern, Christmas fern, and Dutchman’s-breeches. Upland forest on gentler slopes at the northeastern side of the Mill Grove property also support red oak – mixed hardwood forest. Bladdernut, hornbeam, and redbud are present in the under- story and the herbaceous layer includes Virginia bluebells, Dutchman’s-breeches, spring-beauty, wild leek, and star chickweed. Invasive species in the upland sites include woody plants such as Siebold viburnum, winged euonymus, Japanese honeysuckle, wineberry, and multifl ora rose,

218 Natural Areas Inventory Update 2007 and herbaceous species such as periwinkle, English ivy, lesser celandine, garlic mustard, star-of- Bethlehem, daffodils, and Siberian squill. Early successional forests are present in several upland areas, including the mine site. Trees include sycamore, box-elder, white ash, American elm, hackberry, and eastern red cedar. The invasive, non-native Norway maple is also present in several locations. Invasives such as multi- fl ora rose, obtuse-leaved privet, and Oriental bittersweet dominate the shrub layer. The property also contains mowed meadows in the uplands toward Pawling Road, which were not inventoried. Reptiles and Amphibians – Inventory data are not available for this site specifi cally, see Valley Forge National Historical Park above. Birds – Inventory data are not available for this site specifi cally; see Valley Forge National His- torical Park above. Deer Status – Upland forests at the Mill Grove site appear to be severely browsed except on the steepest slopes. Species on which browsing damage was evident included maple-leaf viburnum, American beech, mayapple, and mountain laurel; however, the sparse shrub and herbaceous lay- ers, lack of seedling and sapling trees, and dominance by invasive species are also the result of overabundant deer feeding preferentially on native plants. The combination of heavy browsing pressure on native species and competition from invasives poses a serious threat to native species diversity at this site. Forest regeneration is also affected as highly preferred species such as oaks and tuliptree are browsed repeatedly and cannot grow beyond the browse line. Sugar maple, which is less preferred, may become more prominent in the future. Invasive Plants – Invasives are present throughout the Mill Grove site, a refl ection of its long his- tory of human use. Here we have summarized some of the most serious problems. Lesser celan- dine and moneywort dominate forest fl oor on the fl oodplain in early spring. Japanese knotweed is present along the creek banks in several areas. A colony of Norway maple is established in a small stream valley. Siebold viburnum, obtuse-leaved privet, Japanese barberry, and winged euonymus are scattered throughout and have the potential to increase in abundance. Japanese honeysuckle and garlic mustard are also abundant. Several plants that were probably originally planted at the site, English ivy, periwinkle, daffodils, and Siberian squill are spreading in the woods.

Mont Clare Cliffs and Ravines Mont Clare Cliffs and Ravines site was identifi ed as a priority site in the 1995 Natural Areas Inventory. The site in- cludes steep slopes, outcrops, and wood- ed ravines along the river valley at the dramatic loop made by the river above Mont Clare. The upper slopes provide excellent views of the river valley. Part of the site is managed as Upper Schuylkill Valley County Park. Located in Upper Providence Township, the 154- View of the Schuylkill River from the top of the Mont Clare Cliffs

Natural Areas Inventory Update 2007 219 acre park is accessed from Black Rock Road (Rt. 113). It contains a portion of the Schuylkill East Trail and provides picnicking facilities and river access. The portion of the park north of Rt. 113 is completely undeveloped. Plant Diversity – One hundred and sixty-five (165) species of vascular plants weree iden- tified during 4 visits to the site in 2006; 37 (22.4 percent) were non-native. Native tree diversity was high with 36 species; 64 species of native wildflowers were present (Table 13.4). No Pennsylvania Natural Heritage Program-listed plant species were found. The full list is included in Appendix 13.C.

Table 13.4 — Mont Clare Cliffs and Ravines Plant Diversity

Plant Type Native Introduced Trees 36 9 Shrubs 13 7 Woody vines 2 2 Grasses and sedges 9 1 Ferns 4 0 Wildfl owers 64 18 Totals 128 37

Plant Communities – The riparian strip along the trail and riverbank is characterized by syca- more – (river birch) – box-elder fl oodplain forest. Other species present in addition to those named above include slippery elm, American elm, honey locust, silver maple, and white ash. Native shrubs present are spicebush and bladdernut; in addition invasives shrubs including mul- tifl ora rose, obtuse-leaved privet, and autumn olive are common. Two native vines are abundant: poison-ivy and frost grape. The herbaceous layer in this forest type includes native species such as slender chervil, spring-beauty, false- mermaid, and trout lily; however, inva- sives such as lesser celandine, Japanese knotweed, ground-ivy, common mug- wort, and Indian strawberry often domi- nate the ground surface. Steep slopes along the river valley con- tain a dry oak – mixed hardwood for- est with red, white, black, and chestnut oak, shagbark hickory, pignut hickory, blackgum, white ash, American elm, and occasionally basswood. The under- story includes redbud, hop-hornbeam, Wild columbine on the cliffs at Mont Clare hawthorn, blackhaw and witch-hazel. Shrubs include downy arrow-wood, and occasionally patches of lowbush blueberry or pasture rose. Herbaceous plants include early saxifrage, red columbine, ragwort, common dittany, alum- root, silver-rod, bluestem goldenrod, forest goldenrod, and Solomon’s-seal. Early in the season

220 Natural Areas Inventory Update 2007 chickweed, ivy-leaved speedwell, and bedstraw dominate the lower slopes in some areas, creat- ing a continuous groundcover from which scattered native wildfl owers protrude. Ravines contain the least disturbed natural communities. Ravine forests are of a red oak – mixed hardwood type. Prominent species include red and white oaks, American beech, tuliptree, red maple, sugar maple, and hackberry. The shrub layer is dominated by spicebush or witch-hazel. A diverse array of native herbaceous species is also present including Solomon’s- seal, false Solomon’s-seal, jack-in-the-pulpit, Dutchman’s-breeches, sessile-leaved bellwort, black cohosh, Christmas fern, rue anemone, star chickweed, common yellow violet, white wood aster, sweet cicely, wood geranium, Canada mayfl ower, and hepatica. Norway maple has begun to invade several of the ravines, entering from either the bottom or the top. Japanese honeysuck- le is a nearly continuous groundcover on upland areas between the ravines. Reptiles and Amphibians – Surveys conducted by Marlin Corn as part of this project documented the presence of 7 species of reptiles and amphibians in the Mont Clare Cliffs and Ravines area (Table 13.5). Three additional species noted by Rhoads and Block are indicated by an asterisk.

Northern black racer photographed along the Schuylkill River near Mont Clare

Table 13.5 — Reptiles and Amphibians of Mont Clare Cliffs and Ravines

Salamanders Northern two-lined salamander Northern redback salamander* Frogs and Toads Pickerel frog Green frog Bullfrog American toad Turtles Common snapping turtle Eastern painted turtle Snakes Northern black racer* Eastern garter snake*

* documented by Rhoads and Block

Invasive Plants – Non-native invasive plants are very abundant in fl oodplain areas and lower slopes along the river. This is due to the constant infl ux of seeds or other propagules carried by fl oodwaters as well as human activities along the former canal and navigation system. Up-

Natural Areas Inventory Update 2007 221 lands too, are heavily impacted due to earlier clearing and cultivation. However, steep upper slopes and ravines retain a good diversity of native species. Invasives that should be targeted for control include Norway maple, which is invading several ravines, winged euonymus, and tree-of-heaven.

Schuylkill Canal At the downstream end of the Mont Clare Cliffs and Ravines site, around the loop in the river, are Black Rock Dam, Lock 60, and the 2.5 mile Oakes Reach of the Schuylkill Canal. Extend- ing from Mont Clare to Port Providence, it is one of only two remaining watered sections of the canal (the other is in Manayunk). Lock 60 and the nearby lock tender’s house; have been restored by the Schuylkill Canal Association. The recreation area includes the undeveloped greenway between the canal and the river. Several parcels of state and township land are in- volved. The former desilting basin at the downstream end of the canal occupies a 77.8-acre tract owned by the Common- wealth of Pennsylvania (Figure 13.4). Montgomery County owns a 23.3-acre tract of forested land above the Black Lock 60 of the Schuylkill Canal, restored by the Schuylkill Canal Association Rock Dam and Lock 60 site and Up- per Providence Township owns an additional 32.3 acres of upland forest in the same area. These protected uplands provide a forested backdrop for the historic Lock 60 area.

Other Protected Open Space Lower Perkiomen Valley Park Lower Perkiomen Valley Park is a 98-acre county park located in the fl oodplain of the Perkio- men Creek opposite the John James Audubon Center at Mill Grove. It includes a section of the Perkiomen Trail as well as picnic groves, playgrounds, and open fi elds. Although a tree canopy has been retained in much of the park, mowing and deer browse have removed the shrub and herbaceous layers.

Andruss Island Andruss Island lies in the Schuylkill River 0.6 mile upstream from the mouth of the Perkiomen Creek. Situated in Upper Providence Township, it is owned by the Natural Lands Trust. The 26.9-acre island was deeded to NLT in 1975 by Alcoa Standard Corporation with the condition that it be used exclusively as a natural area. This site is not being actively managed.

222 Natural Areas Inventory Update 2007 The island is almost entirely forested; a scoured sycamore – box-elder fl oodplain forest charac- terizes the upsteam end. As is typical of river islands, the downstream end is higher and con- tains a more mature forest containing a mixture of fl oodplain and upland species. Tuliptree and American beech are common on terraces; sugar maple is also abundant. Other canopy species include green ash, black walnut, and American elm. The understory is dominated by spicebush; in addition, a large colony of pawpaw is present. Typical herbaceous species include Virginia bluebells, jack-in-the-pulpit, and green dragon. The invasive, non-native Japanese stiltgrass is abundant throughout.

Recommendations Connectivity and Land Protection Priorities • Seek protection of all forested slopes and ravines along the river between Mont Clare and Route 113. • Extend the Schuylkill East Trail from Black Rock Dam to Upper Schuylkill Valley Park as envisioned in the open space plan for Montgomery County. • Seek permanent protection for the lands of the Montgomery County Geriatric Center. • Protect/acquire inholdings along Dreibelbis Road. • Establish a Perkiomen Trail connection with Evansburg State Park; ideally this would involve fee or easement acquisition to protect forested slopes adjacent to the south end of the park. • Seek protection of lands along the Perkiomen Creek at the downstream end of Lower Perkiomen Valley Park. • Seek protection for forested lands along Mine Run across Egypt Road from the Mill Grove site.

Management Priorities • Reduce deer density in Valley Forge National Park and other managed sites. • Reduce mowing in Lower Perkiomen Valley Park. • Discourage off-trail bicycling to protect reptile and amphibian habitat on the fl oodplain of the Schuylkill River.

Education and Interpretation • Exhibits should be developed at Valley Forge National Historical Park and the Audubon Center at Mill Grove to educate visitors regarding the ecological problems caused by deer overabundance and invasive species.

Natural Areas Inventory Update 2007 223 Bibliography Anonymous. 2004. Shaping Our Future: Open Space, Natural features, and Cultural Resources Plan. Montgomery County Planning Commission, Norristown, PA. Commonwealth of Pennsylvania. 2005. Pennsylvania Code, Title 25, Chapter 93. Water Quality Standards. Harrisburg, PA. Daeschler, Edward B., Mathew C. Lamanna, and Margaret Carfi oli. 2005. On the trail of an important ice age fossil deposit. Park Science 32(2): 31-36. Evans, F. Harold. 1980. Historical Sketches of Copper and Lead Mining in Montgomery County, Pennsylvania. Special publication No. 2, Friends of Mineralogy, Pennsylvania Chapter, Inc. Fike, Jean. 1999. Terrestrial and Palustrine Plant Communities of Pennsylvania. Commonwealth of Pennsylvania, Department of Conservation and Natural Resources, Bureau of Forestry, Harrisburg, PA. Geist, G.W. 1907. The story of the fi rst Pennsylvania copper mines. Mineral Collector 14: 81-87. Geyer, Alan R. and William H. Bolles. 1979. Outstanding Scenic Geologic Features of Pennsylvania, Environmental Geology Report 7. Pennsylvania Department of Conservation and Natural Resources, Bureau of Topographic and Geologic Survey, Harrisburg, PA. Lundgren, J.A., A. F. Davis, B. Barton, J.R. Belfonti, D.J. Cameron, N. Clupper, J.L. Farber, and J.R. Kunsman. 1995. A Natural Areas Inventory of Montgomery County, Pennsylvania. The Pennsylvania Science Offi ce of The Nature Conservancy, Middletown, PA. National Park Service. 2006. Valley Forge National Park White-tailed Deer Management Plan and Environmental Impact Statement, Final Internal Scoping Report. http://www.nps.gov/vafo/parkmgmt/white-tailed-deer.htm, accessed February 2007. Podniesinski, G., L. Snedon, J. Lundgren, H. Devine, B. Slocumb, and F. Koch. 2005. Vegetation Classifi cation and Mapping of Valley Forge National Historical Park. Technical Report NPS/ NER/NRTR—2005/028. National Park Service, Philadelphia, PA. Pennsylvania Breeding Bird Atlas http://bird.atlasing.org/Atlas/PA/Main, accessed 1/30/2007. Pennsylvania Fish and Boat Commission. 2006. http://www.fi sh.ap.us/shad.htm, accessed 10/13/2006. Pennsylvania Natural Heritage Program database http://www.naturalheritage.state.pa.us, accessed 1/15/2007. Rhoads, Ann F., Douglas Ryan, and Ella W. Aderman. 1989. Land Use Study of Valley Forge National Historical Park. Unpublished report to the National Park Service, Philadelphia, PA. Shultz, Charles H. 1999. The Geology of Pennsylvania. Pennsylvania Geological Survey, Harrisburg, PA.

224 Natural Areas Inventory Update 2007 Tiebout, Harry M. 2003. An Inventory of the herpetofauna of Valley Forge National Historical Park. Technical Report NPS/PHSO/NRTR-03/088. National Park Service, Philadelphia, PA. Wherry, E.T. 1908. The Newark copper deposits of southeastern Pennsylvania. Economic Geologist 3: 726-738. White, William B. 1976. Geology and Biology of Pennsylvania Caves. Commonwealth of Pennsylvania, Department of Conservation and Natural resources, Bureau of Topographic and Geologic Survey, Harrisburg, PA. Yahner, Richard H., Bradley D. Ross, Gregory S. Keller, and David S. Klute. 2001. Comprehensive inventory program for birds at six Pennsylvania national parks. Technical Report NPS/PHSO/NRTR-01/084. National Park Service, Philadelphia, PA.

Natural Areas Inventory Update 2007 225 APPENDIX 13.A Combined Bird List for Valley Forge National Park (from Breeding Bird Atlas and Yahner et al)

Bird Breeding Evidence** Status Acadian Flycatcher x, bbs Alder Flycatcher American Black Duck bbs Audubon watchlist American Coot American Crow x, bbs American Goldfi nch x, bbs American Kestrel x, bbs American Redstart x, bbs American Robin x, bbs American Tree Sparrow American Woodcock x Baltimore Oriole x, bbs Barn Swallow x, bbs Barred Owl Bay-breasted Warbler Belted Kingfi sher x, bbs Black Vulture x Black-and-white Warbler x, bbs Black-billed Cuckoo x Blackburnian Warbler Blackpoll Warbler x Black-throated Blue Warbler Audubon watchlist Black-throated Green Warbler Blue Grosbeak* bbs Bluejay x, bbs Blue-gray Gnatcatcher x, bbs Blue-headed Vireo Blue-winged Warbler x, bbs USFWS management concern Bobolink x Broad-winged Hawk bbs Brown Creeper Brown Thrasher x, bbs Brown-headed Cowbird x, bbs Buffl ehead Canada Goose x, bbs Canada Warbler Audubon watchlist

Natural Areas Inventory Update 2007 377 Cape May Warbler Carolina Chickadee x Carolina Wren x, bbs Cedar Waxwing x, bbs Cerulean Warbler* bbs Audubon watchlist, USFWS management concern Chestnut-sided Warbler USFWS management concern Chimney Swift x, bbs Chipping Sparrow x Common Goldeneye Common Grackle x, bbs Common Nighthawk Common Raven Common Snipe S3 - Pa vulnerable Common Yellowthroat x, bbs Cooper’s Hawk x Dark-eyed Junco Double-crested Cormorant Downy Woodpecker x, bbs Eastern Bluebird x Eastern Kingbird x, bbs Eastern Meadowlark x, bbs USFWS management concern Eastern Phoebe x, bbs Eastern Screech Owl Eastern Towhee x, bbs Eastern Wood-peewee x, bbs European Starling x, bbs Field Sparrow x, bbs USFWS management concern Fish Crow Fox Sparrow Golden Eagle Golden-crowned Kinglet Grasshopper Sparrow x USFWS management concern Gray Catbird x, bbs Great Blue Heron x Great Crested Flycatcher x, bbs Great Horned Owl x Green Heron bbs Hairy Woodpecker x, bbs Hermit Thrush Herring Gull Hooded Merganser Hooded Warbler* bbs

378 Natural Areas Inventory Update 2007 Horned Lark House Finch x, bbs House Sparrow x, bbs House Wren x, bbs Indigo Bunting x, bbs Kentucky Warbler x, bbs Killdeer x, bbs Least Flycatcher Least Sandpiper Lesser Scaup Lesser Yellowlegs Lincoln’s Sparrow Long-eared Owl S2 - State imperiled Louisiana Waterthrush x Audubon watchlist, USFWS management concern Magnolia Warbler Marsh Wren S2/S3 - Pa imperiled/vulnerable Mallard x, bbs Mourning Dove x, bbs Nashville Warbler Northern Cardinal x, bbs Northern Flicker x, bbs USFWS management concern Northern Harrier x S3 – PA vulnerable, USFWS management concern Northern Mockingbird x, bbs Northern Parula x, bbs Northern Rough-winged Swallow x, bbs Northern Saw-whet Owl S3 – PA vulnerable Orchard Oriole x, bbs Osprey PA threatened Ovenbird x, bbs Palm Warbler Pectoral Sandpiper Philadelphia Vireo Pied-billed Grebe S3 – PA vulnerable Pileated Woodpecker x Pine Warbler Prairie Warbler x, bbs Purple Ffnch x Red-bellied Woodpecker x, bbs Red-breasted Nuthatch Red-eyed Vvreo x, bbs Red-headed Woodpecker x USFWS management concern Red-shouldered Hawk x USFWS management concern

Natural Areas Inventory Update 2007 379 Red-tailed Hawk x Red-winged Blackbird x, bbs Ring-billed Gull Ring-necked Duck Rock Dove x, bbs Rose-breasted Grosbeak x, bbs Ruby-crowned Kinglet Ruby-throated Hummingbird x Savannah Sparrow Scarlet Tanager x, bbs Sharp-shinned Hawk x Solitary Sandpiper Song Sparrow x, bbs Spotted Sandpiper bbs Swainson’s Thrush Swamp Sparrow x Tennessee Warbler Tree Swallow x, bbs Tufted Titmouse x, bbs Tundra Swan Turkey Vulture x, bbs Veery x USFWS management concern Vesper Sparrow x Warbling Vireo x, bbs White-breasted Nuthatch x, bbs White-eyed Vireo x, bbs White-throated Sparrow Willow Flycatcher x Winter Wren Wood Duck x, bbs Wood Thrush x, bbs Audubon watchlist, USFWS management concern Worm-eating Warbler x, bbs Audubon watchlist, USFWS management concern Yellow Warbler x Yellow-bellied Sapsucker Yellow-billed Cuckoo x, bbs Yellow-breasted Chat* bbs Yellow-rumped Warbler Yellow-throated Vireo x

* not recorded by Yahner et al. ** x=recorded as present during the breeding season by Yahner et al. bbs=recorded as confi rmed, probable, or possible breeders during the 1984-1989 Breeding Bird Atlas survey.

380 Natural Areas Inventory Update 2007 APPENDIX 13.B John James Audubon Center at Mill Grove – Plant List Partial List of the Vascular Plants of John James Audubon Center at Mill Grove as recorded by Ann Rhoads and Tim Block April 18, 2006

Steep Tributary Disturbed Scientifi c Name Common Name N/I Floodplain Slopes Stream Valleys Areas Ferns and other Spore-bearing Plants Dryopteris marginalis marginal wood fern N x Equisetum arvense fi eld horsetail N x Onoclea sensibilis sensitive fern N x x Polystichum acrostichoides Christmas fern N x Grasses, Sedges, and Rushes Carex albicans a sedge N x Carex brevicrinus short-hair sedge N x Carex communis a sedge N x Danthonia spicata poverty grass N x Luzula multifl ora woodrush N x Phalaris arundinacea reed canary grass I x Phragmites australis common reed I x Wildfl owers and Other Herbaceous Plants Acorus calamus sweet fl ag I x Alliaria petiolata garlic mustard I x x x x Allium tricoccum wild leek, ramps N x x x Allium vineale fi eld garlic I x Arabis laevigata smooth rockcress N x Arctium minor burdock I Arisaema triphyllum jack-in-the-pulpit N x Asarum canadense wild ginger N x Asplenium platyneuron ebony spleenwort N x Boehmeria cylindrica false nettle N x Callitriche palustris water starwort N x Cardamine bulbosa bittercress N x Cardamine hirsuta hairy bittercress I Chelodonium major greater celandine I Chelone glabra turtlehead N x Claytonia virginica spring-beauty N x x x x Dicentra cucullaria Dutchman’s-breeches N x x x Epifagus virginiana beechdrops N x

Natural Areas Inventory Update 2007 381 Erythronium americanum trout lily N x x x Euphorbia esula leafy spurge I x Eurybia divaricata white wood aster N x Floerkia proserpinacoides false mermaid N x x x Galium aparine bedstraw N x Geranium maculatum wood geranium N x x Geum canadense white avens N x x Glechoma hederacea ground-ivy I x Hemerocallis fulva orange daylily I x x Hesperis matronalis dames’-rocket I x Hieracium caespitosum hawkweed N x Houstonia caerulea bluets N x Hydrophyllum virginianum Virginia waterleaf N x Impatiens capensis jewelweed N x Lamium purpureum purple dead-nettle I x Leonurus cardiaca common motherwort I x Lysimachia numularia moneywort I x Mertensia virginica Virginia bluebells N x x Narcissus poeticus poet’s narcissus I Narcissus pseudonarcissus daffodil I x x Nasturtium offi cinale watercress N x Ornithogalum umbellatum star-of-Bethlehem I x Parietaria pensylvanica pellitory N x Plantago lanceolata narrow-leaved plantain I x Podophyllum peltatum mayapple N x x x x Polygonatum pubescens Solomon’s-seal N x Fallopia japonica Japanese knotweed I x Persicaria perfoliata mile-a-minute weed I x Prenanthes sp. rattlesnake root N x Ranunculus abortivus small-fl owered crowfoot N x x Ranunculus fi caria lesser celandine I x x Rubus phoenicolasius wineberry I x x Rumex obtusifolius bitter dock I x Saxifraga virginiensis early saxifrage N x Scilla siberica Siberian squill I x Smilacina racemosa false Solomon’s-seal N x Solidago caesia bluestem goldenrod N x Stellaria media chickweed I x x Stellaria pubera star chickweed N x Symphyotrichum laterifl orum calico aster N x Symplocarpus foetidus skunk-cabbage N x

382 Natural Areas Inventory Update 2007 Taraxacum offi cinale dandelion I x x Thalictrum dioicum early meadow-rue N x Typha latifolia common cat-tail N x Uvularia sessilifolia sessile-leaved bellwort N x Verbascum thapsus common mullein I Veronica americana American speedwell N x Vinca minor common periwinkle I x Viola sororia common blue violet N x x Trees, Shrubs, and Woody Vines Acer negundo box-elder N x x Acer platanoides Norway maple I x x x Acer rubrum red maple N x Acer saccharinum silver maple N Acer saccharum sugar maple N x x x Berberis thunbergii Japanese barberry I x Betula lenta black birch N x Carpinus caroliniana hornbeam N x Carya ovata shagbark hickory N Celastrus orbiculatus Oriental bittersweet I x Celtis occidentalis hackberry N x x x Cercis canadensis redbud N x Cornus amomum silky dogwood, kinnikinick N x Euonymus alatus winged euonymus I x x Euonymus fortunei wintercreeper I x Fagus grandifolia American beech N x Fraxinus americana white ash N x x Hamamelis virginiana witch-hazel N x Hedera helix English ivy I x Juglans nigra black walnut N x Juiperus virginiana eastern red-cedar N x x Kalmia latifolia mountain laurel N x Ligustrum obtusifolium obtuse-leaved privet I x x Lindera benzoin spicebush N x x x Liriodendron tulipifera tuliptree N x x Lonicera japonica Japanese honeysuckle I x x x Lonicera maackii Amur honeysuckle I x Maclura pomifera osage-orange I Malus hyb. crabapple x Morus alba white mulberry I x Parthenocissus quinquefolia Virginia creeper N x Platanus occidentalis sycamore N x x

Natural Areas Inventory Update 2007 383 Prunus avium European bird cherry I x x Prunus serotina wild black cherry N x Quercus alba white oak N x x x Quercus montana chestnut oak N x Quercus palustris pin oak N Quercus rubra red oak N x Quercus velutina black oak N x Rosa multifl ora multifl ora rose I x x x Rubus occidentalis black raspberry N x Staphylea trifolia bladdernut N x Tilia americana basswood N x Toxicodendron radicans poison-ivy N x x Tsuga canadensis Canada hemlock N x Ulmus americana American elm N x x x Vaccinium pallidum lowbush blueberry N x Viburnum acerifolium maple-leaved viburnum N x Viburnum opulus guelder-rose I x Viburnum sieboldii Siebold viburnum I x Vitis vulpina frost grape N x

384 Natural Areas Inventory Update 2007 APPENDIX 13.C Mont Clare Cliffs and Ravines - Plant List

Native or Floodplain Slopes and House Common Name Scientifi c Name Ravines Introduced Forest Ridgetops Site Ferns and Other Spore-Bearing Plants ebony spleenwort Asplenium platyneuron Nxx fragile fern Cystopteris fragilis Nx rockcap fern Polypodium virginianum Nx Christmas fern Polystichum acrostichoides Nx Grasses, Sedges, and Rushes sweet vernal grass Anthoxanthum odoratum Ix autumn bent Agrostis perennans Nx sedge Carex blanda Nxx sedge Carex laxifl ora Nxx Pennsylvania sedge Carex pensylvanica Nx sedge Carex platyphylla Nx poverty grass Danthonia spicata Nx rice cutgrass Leersia virginica Nx woodrush Luzula multifl ora Nx wirestem muhly Muhlenbergia frondosa Nx Wildfl owers and Other Herbaceous Plants garlic mustard Alliaria petiolata Ixxx fi eld garlic Allium vineale Ix wild columbine Aquilegia canadensis Nx smoooth rockcress Arabis laevigata Nxx lyre-leaved rockcress Arabis lyrata Nx wild sarsaparila Aralia nudicaulis Nxx jack-in-the-pulpit Arisaema triphyllum Nx common mugworts Artemisia vulgaris Ix toothwort Cardamine concatenata Nxxx hairy bittercress Cardamine hirsuta Ixxx slender chervil Chaerophyllum procumbens Nx pipsissewa Chimaphila maculata Nx black snakeroot Actaea racemosa Nx enchanter’s-nightshade Circaea canadensis Nx springbeauty Claytonia virginica Nxxx honewort Cryptotaenia canadensis Nx wild basil Cunila origanoides Nx Dutchman’s-breeches Dicentra cucullaria Nx

Natural Areas Inventory Update 2007 385 barrens-strawberry Duchesnia indica Ix beechdrops Epifagus virginiana Nx pilewort Erechtites hieracifolium Nx daisy fl eabane Erigeron philadelphicum Nx trout lily Erythronium americanum Nx white snakeroot Eupatorium rugosum Nx x white wood aster Eurybia divaricata Nxx false mermaid Floerkia proserpinacoides Nxx cleavers Galium aparine Nxxx wild licorice Galium circaezans Nx white bedstraw Gallium mollugo Ix wood geranium Geranium maculatum Nx white avens Geum canadense Nx x ground-ivy Glechoma hederacea Ix thin-leaved sunfl ower Helianthus decapetalus Nx liverleaf Hepatica nobilis var. obtusa Nx dame’s-rocket Hesperis matronalis Ix alumroot Heuchera americana Nx hawkweed Hieracium paniculatum Nx bluets Houstonia caerulea Nx wild lettuce Lactuca canadensis Nx Canada mayfl ower Maianthemum canadense Nx moonseed Menispermum canadense Nx Indian-pipes Monotropa unifl ora Nx star-of-Bethlehem Ornithogalum umbellatum Ix sweet-cicely Osmorhiza claytonii Nxx aniseroot Osmorhiza longistylis Nx ragfwort Packera obovata Nx perilla Perilla frutescens Ix pokeweed Phytolacca americana Nx mayapple Podophyllum peltatum Nxx Solomon’s-seal Polygonatum pubescens Nx low smartweed Persicaria longisetum Ix jumpseed Persicaria virginianum Nx rattlesnake-root Prenanthes sp. Nx small-fl owered crowfoot Ranunculus abortivus Nx bulbous buttercup Ranunculus bulbosus Ix lesser celandine Ranunculus fi caria Ixx curly dock Rumex crispus Ix bloodroot Sanguinaria canadensis Nxxx early saxifrage Saxifraga virginiensis Nx

386 Natural Areas Inventory Update 2007 bur cucumber Sicyos angulatus Nx false Solomon’s-seal Maianthemum racemosum Nx horse-nettle Solanum carolinense Nx forest goldenrod Solidago arguta Nx silver-rod Solidago bicolor Nx bluestem goldenrod Solidago caesia Nxx Canada goldenrod Solidago canadensis Nx smooth goldenrod Solidago gigantea Nx wrinkle-stem goldenrod Solidago rugosa Nx chickweed Stellaria media Ixx star chickweed Stellaria pubera Nx blue wood aster Symphyotrichum cordifolium Nx smooth blue aster Symphyotrichum laeve var. concinnus Nx panicled aster Symphyotrichum lanceolatum Nx tall meadow-rue Thalictrum pubescens Nx rue-anemone Thalictrum thalictroides Nx bellwort Uvularia perfoliata Nx fi eld speedwell Veronica arvensis Ix ivy-leaved speedwell Veronica hederifolia Ixx thyme-leaved speedwell Veronica serpyllifolia Ix common yellow violet Viola pubescens Nx common blue violet Viola sororia Nx striped violet Viola striata Nx Trees, Shrubs, and Woody Vines box-elder Acer negundo Nx Norway maple Acer platanoides Ixxx red maple Acer rubrum Nxxx silver maple Acer saccharinum Nx sugar maple Acer saccharum Nxx tree-of-heaven Ailanthus altissima Ix European alder Alnus glutinosa Ixx pawpaw Asimina triloba Nx Japanese barberry Berberis thunbergii Ix river birch Betula nigra Nx bitternut hickory Carya cordiformis Nx pignut hickory Carya glabra Nx pecan Carya illinoensis Ix shagbark hickory Carya ovata Nx mockernut hickory Carya tomentosa Nx x Chinese chestnut Castanea mollisima I x Oriental bittersweet Celastrus orbiculatus Ix

Natural Areas Inventory Update 2007 387 hackberry Celtis occidentalis Nx redbud Cercis canadensis Nxx fl owering dogwood Cornus fl orida N cockspur hawthorn Crataegus crusgalli Nx fanleaf hawthorn Crataegus macrosprerma Nx autumn-olive Elaeagnus umbellata Ix winged euonymus Euonymus alatus Ix American beech Fagus grandifolia Nxx white ash Fraxinus americana Nxxx ginkgo Ginkgo biloba Ix honeylocust Gleditsia triacanthos Nx witch-hazel Hamamelis virginiana Nxx rose-of-sharon Hibiscus syriacus Ix wild hydrangea Hydrangea arborescens Nx eastern red-cedar Juniperus virginiana Nx mountain laaurel Kalmia latifolia Nx obtuse-leaved privet Ligustrum obtusifolium Ix spicebush Lindera benzoin Nxx tuliptree Liriodendron tulipifera Nxx Japanese honeysuckle Lonicera japonica Ix x osage-orange Maclura pomifera Ix white mulberry Morus alba Ix blackgum Nyssa sylvatica Nx hop hornbeam Ostrya virginiana Nx Virginia pine Pinus virginiana Nx sycamore Platanus occidentalis Nxx European bird cherry Prunus avium Ix wild black cherry Prunus serotina Nx choke cherry Prunus virginiana Nx red oak Quercus alba N scarlet oak Quercus coccinea Nx chestnut oak Quercus montana Nxx red oak Quercus rubra Nxx black oak Quercus velutina Nxx pinxter-fl ower Rhododendron periclymenoides Nx pasture rose Rosa carolina Nx multifl ora rose Rosa multifl ora Ix blackcap Rubus occidentalis Nx wineberry Rubus phoenicolasius Ix x sassafras Sassafras albidum Nx bladdernut Staphylea trifolia Nx

388 Natural Areas Inventory Update 2007 basswood Tilia americana Nx poison-ivy Toxicodendron radicans Nx x Canada hemlock Tsuga canadensis Nx American elm Ulmus americana Nx x slippery elm Ulmus rubra Nx lowbush blueberry Vaccinium pallidum Nx deerberry Vaccinium stamineum Nx maple-leaf viburnum Viburnum acerifolium Nxx blackhaw Viburnum prunifolium Nx downy arrow-wood Viburnum rafi nesquianum Nx frost grape Vitis vulpina Nx

Natural Areas Inventory Update 2007 389 390 Natural Areas Inventory Update 2007