One of the Five Best Preserved Areas in the Crum Woods

Of the over 200 acres in the Crum Woods, five unique locations are prominent for their excellent state of preservation: the Wister Forest, Martin Forest, Trillium Slope, Skunk-Cabbage Hollow, and the Southern Red Oak Forest. These sites have been subject to many of the pressures face by natural areas, such as invasive species competition, deer browsing, trash dumping, and trail use, but have remained excellent spaces with mature trees, beneficial and endangered species, and wildlife value. Through this series of articles, I will explore each space and share what I’ve learned about their special characteristics, plants, wildlife, and the struggles they face. I encourage you to visit each beautiful area yourself!

Although, Trillium Slope looks most impressive in April when the trillium are in bloom, it is a quiet, peaceful, and fascinating location to visit at any time of the year. photo credit: A. Bacon

Although, Trillium Slope looks most impressive in April when the trillium are in bloom, it is a quiet, peaceful, and fascinating location to visit at any time of the year. Trillium Slope is a steep area about three acres in size, located along the creek opposite the Holly Collection and meadow. It can be accessed from the Leiper-Smedley trail at the Crum Ruins.

Trilliums are typically in full bloom in late April. photo credit: R. Robert

Although previously an oak-hickory forest, Trillium Slope is now known as a tulip-beech-maple forest. One of the many reasons American beech, tuliptree, and maple now dominate is because they need less sunlight to germinate. American Indians routinely burned the forests which allowed hickories and oaks to resprout and thrive with the increased sunlight. In recent years, forests in the northeast are rarely burned, and therefore shade tolerant species have taken over.

Trillium Slope is known for its trillium of three different varieties: T. erectum, T. luteum, and T. grandiflorum. Although Mike Rolli, our former Crum Woods Restoration Assistant, suspects that most or all of these trillium were planted in the Crum Woods, T. erectum and T. grandiflorum are native to Pennsylvania, so could occur here naturally. T. luteum, however, is native to Michigan and southeastern states, stretching down as far south as Alabama, and as far west as Tennessee. Much of the vegetation in and around the Oak Knoll ruins is a result of the Hinksons’ planting, so it is quite likely that they or a previous landowner planted the trillium. Evidence of the Hinksons’ gardens still stands including several Japanese tree lilacs, deutzia, pachysandra, and the remains of garden walls and other structures. For more information on the history and horticulture of Oak Knoll, check out this post.

Several invasive plants plague trillium slope including Kalopanax septemlobus.

Trillium Slope has a rich herbaceous layer composed of Virginia bluebells, Jack-in-the-pulpit, Mayapple, and trillium. Ten years ago, Trillium Slope also contained rare plants such as dwarf ginseng and goldenseal, but they have since disappeared. Several invasive plants plague trillium slope, such as Pachysandra terminalis (Japanese pachysandra), Kalopanax septemlobus (castor aralia), Hedera helix (English ivy), and Euonymus alatus (burning bush).

A large, twisted ironwood tree, Carpinus caroliniana, hangs over Crum Creek at the bottom of the slope. photo credit: A. Bacon

A large, twisted ironwood tree, Carpinus caroliniana, hangs over Crum Creek at the bottom of the slope. A mud flat with important plant and wildlife value is also located along the edge of the creek and stretches farther up and downstream. Occasionally, emergent aquatic vegetation can be found in this mudflat, an area in which plants are rooted in the creek bed but have leaves or flowers that are visible above the water. The mud flat is also sometimes used for turtle nesting. As we walked along the creek, we saw several large turtles sunning on a log.

Occasionally, emergent aquatic vegetation can be found in this mudflat, an area in which plants are rooted in the creek bed but have leaves or flowers that are visible above the water. photo credit: A. Bacon

Trillium Slope is a lovely place to take a walk, in spring or any time of the year; a more tranquil spot in the Crum Woods would be hard to find. Be sure to visit the Southern Red Oak Forest while you are nearby.

The post A Spring Stroll through the Beautiful Trillium Slope appeared first on Scott Arboretum & Gardens.

Southern Red Oak Forest: One of the Five Best Preserved Areas in the Crum Woods

This President’s Day, I am reminded of history found in the Southern Red Oak Forest section of the Crum Woods. While this section of the woods is one of the five unique locations prominent for their excellent state of preservation (the Wister Forest, Martin Forest, Trillium Slope, Skunk-Cabbage Hollow, and the Southern Red Oak Forest), it also has an interesting history of human use.

Turtles caught sunbathing along the Crum Creek. photo credit: R. Robert

As you hike along the trail, you will discover amazing native plants recovering from the formerly-high deer pressure, and odd man-made additions. You may notice the remains of an old powder mill, which was in use during the American Revolution.

We believe these were the poles for the power lines when, in the 1920s, the college supplied its own power from the dam. photo credit: R. Robert

If you look up during your exploration, you may see odd man-made poles along the trail. We believe these were the poles for the power lines when, in the 1920s, the college supplied its own power from the dam.

This portion of the 200-acre Crum Woods encircles the township/college leaf mulch processing center located off of Avondale Road near the entrance to the Smedley-Leiper Trail. photo credit: R. Robert

This portion of the 200-acre Crum Woods encircles the township/college leaf mulch processing center located off of Avondale Road near the entrance to the Smedley-Leiper Trail. This site has ecological importance: the endangered native southern red oak, Quercus falcata, has five mature specimens towering over the forest canopy here.

Various native oaks grace this part of the Crum Woods. photo credit: R. Robert

This native tree species has reddish brown fall color and produces acorns biennially, providing food for wildlife as well as nesting sites and shelter. It also serves as a larval host for butterflies and moths. Commercially, the lumber is used for construction and furniture.

Growing alongside the southern red oak is the fellow native Querucs velutina, black oak. Black oaks attract songbirds, ground birds, and mammals by providing a food source, acorns.

At about boot height in this region of the Crum Woods, you will see the resurgence of the once-dominate maple leaf viburnum, Viburnum acerifolium. photo credit: R. Robert

At about boot height in this region of the Crum Woods, you will see the resurgence of the once-dominate maple leaf viburnum, Viburnum acerifolium. A generation ago, our eastern forests were dominated by this native shrub with aspiring botanists acing their botany quizzes because it was a prolific, easy to identify plant in the woods.

This native, like most viburnums, produces attractive, conspicuous flowers and berries. The flowers are recognized by pollination ecologists as attracting large numbers of native bees. The berries are a source of food for birds and mammals.

Mayapples grace the under-story in this region of the Crum Woods. photo credit: R. Robert

Mike Rolli, our former Crum Woods specialist, attributed the revival of this ecologically important shrub to the deer cull which suppressed over-browsing in the Crum Woods.

Crum Creek flows peaceful through the woods. photo credit: R. Robert

Take a winter walk to explore history and native ecology resurging in this area of the Crum Woods.

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This article is part of an ongoing column called the Crum Woods Chronicle. The Crum Woods Chronicle will be periodic updates and observations about subjects related to natural history, interesting species found in and around the Crum Woods, and exciting events you can get involved in. My hope is that some of these topics will interest you, strengthen your connection to the Crum Woods, and inspire you to explore your backyard a little more often.

Natural areas do not maintain their character and quality independently, especially when they are heavily used by people and embedded in urban environments. Educating yourself about aspects of the Crum Woods that interest you and understanding how your individual use of the Crum Woods impacts it (and how you can reduce that impact!) are important steps every one of us should take.

“In the end we will conserve only what we love; we will love only what we understand; and we will understand only what we are taught.” –Baba Dioum

The post Red Oaks and the American Revolution appeared first on Scott Arboretum & Gardens.

photo by Rick Leche

by Melita Schmeckpeper, 2017-2018 Education Intern

The Crum Woods is home to a diverse group of plants and animals, but to many visitors the identities of these species is often a mystery.  While field guides are great for learning new species, you may not have one on hand right when you need it the most— many birders and naturalists have had the frustrating experience of watching an interesting but mysterious bird fly off into the distance unidentified.  

A Crum Woods biodiversity guide can be found in iNaturalist.

Luckily, a new project orchestrated by Swarthmore professor and Crum Woods Stewardship Committee co-chair Liz Nichols aims to make it easier for anyone with a smartphone to learn about what lives in Crum Woods. Using iNaturalist, an app and website that functions as a social network for citizen scientists, Liz and her students are in the process of developing an easily-accessible guide to the plant and animal diversity of the woods. Their Crum Woods Biodiversity Guide, which currently lists the woods’ bird and plant species, can be found on iNaturalist here.

iNaturalist allows people to share their observations of wild species, help each other with identification, and participate in larger projects that gather useful data for a variety of biodiversity-related research projects. By installing the app on your smartphone, you can access the Crum Woods Biodiversity Guide on your phone, record your own observations, and share your findings with others. For those who prefer not to use a smartphone while exploring the woods, the guide can also be printed in a variety of convenient formats.

This time of year, the Crum Woods is home to a variety of birds including woodpeckers, hawks, and owls. photo credit: R. Robert

This time of year, the Crum Woods is home to a variety of birds including woodpeckers, hawks, and owls. Stop by the trailheads or arboretum office to pick up a flyer that lists the woods’ winter species and gives instructions for accessing iNaturalist.  Trail maps are also available.

While enjoying some birdwatching can be a great way to brighten up a winter walk, be sure to check back in the spring as well: many migrating bird species will arrive as the weather warms. Overall, the Crum Woods is home to over 140 bird species. Spring and summer will also be a great time to use iNaturalist to help you learn more about the woods’ plant species, which are also included in the new Biodiversity Guide.

So how did the new Biodiversity Guide come into being?  In the past, Scott Arboretum has had printed checklists available for birdwatchers. When it came time to update these lists, Professor Liz Nichols suggested that moving them to iNaturalist would be a great way to make them more interactive, accessible, and easy to update. She recruited two students from her conservation biology class who were familiar with iNaturalist, Amanda Carrillo-Perez ‘19 and Natalie LaScala ‘19, to build the guide. In the past, creating a checklist complete with images and species descriptions would be a lengthy endeavor.  Now, instead of basically writing their own field guide, Amanda and Natalie could draw on iNaturalist’s access to vetted open source images and text.  Impressively, they finished the Crum Woods bird guide in a few days, and immediately moved on to creating a guide to the woods’ vascular plants.  

Using iNaturalist, you can identify plants while out on a hike in the Crum Woods. photo credit: R. Robert

Last spring, Liz tested using iNaturalist to increase students’ interaction with the woods by including it in activities in her conservation biology class. It was also used by an introductory biology course taken by over a hundred first-year students. According to Liz, this helped raise campus enthusiasm about iNaturalist and the Crum Woods, and she hopes to continue to build on this interest.

Considering how important public enthusiasm is to conservation efforts locally and internationally, iNaturalist not only represents a way to make learning about local flora and fauna easier and more fun, but also serves as a way to emphasize the importance of protecting places like the Crum Woods.  By helping us see the woods in greater detail, iNaturalist and the new Crum Woods Biodiversity Guide demonstrate how complex and wonderful this 220 acre section of Swarthmore’s campus truly is.

_____________________________________________________________________________________________________________________________________

This article is part of an ongoing column called the Crum Woods Chronicle. The Crum Woods Chronicle will be periodic updates and observations about subjects related to natural history, interesting species found in and around the Crum Woods, and exciting events you can get involved in. My hope is that some of these topics will interest you, strengthen your connection to the Crum Woods, and inspire you to explore your backyard a little more often.

Natural areas do not maintain their character and quality independently, especially when they are heavily used by people and embedded in urban environments. Educating yourself about aspects of the Crum Woods that interest you and understanding how your individual use of the Crum Woods impacts it (and how you can reduce that impact!) are important steps every one of us should take.

“In the end we will conserve only what we love; we will love only what we understand; and we will understand only what we are taught.” –Baba Dioum

The post Winter Birding with iNaturalist appeared first on Scott Arboretum & Gardens.

Martin Forest: One of the Five Best Preserved Areas in the Crum Woods

As we enter fall color season, we continue our series discussing the five best preserved areas in the Crum Woods. Martin Forest is a 30 acre tract of nearly/entirely forested land, and an ideal area to experience autumn color. This old-growth stand has been described by Roger Latham, an ecologist and conservation biologist, as an extraordinary piece of living history. To give a hiker perspective on the importance of Martin Forest, most of the Crum Woods is mature second-growth forest.

An ancient hemlock towering over the tree canopy in the Martin Forest. photo credit: R. Robert

Old-growth forests are natural forests that have developed over a long time, generally at least 120 years, without experiencing any severe, stand-replacing disturbance— fire, windstorms, or logging. Characteristics of an old-growth forest that are present in the Martin Tract include:

1. “Tip-ups” (where the trees have tipped over)
2. Some trees close to their maximum longevity
3. A natural regeneration of successional and dominant tree species within canopy gaps or on decaying logs, and multi-aged stand structure.
4. Associations of long-lived, shade-tolerant tree species (beech, hemlock, red maple)
5. Land preserved under one owner between 1870-1889

A characteristics of an old-growth forest, tip-ups can be found along the trails. photo credit: R. Robert

Located in the shadow of the Blue Route (Route 476) in Springfield, PA, the Martin Forest is bordered by Smedley Park (120 acres) and Jane Lownes Park (23.4 acres). This hemlock-mixed oak forest contains a CDCA sewer line right-of-way along the Crum Creek. A trailhead can found at the rear of Smedley Park where the parking lot ends with playing fields.

Decaying logs surround by an understory of skunk cabbage is another characteristic of an old-growth forest. photo credit: R. Robert

This tract has been studied for centuries. John Harshberger (1869-1929), professor of  botany at University of Pennsylvania, president of the Botanical Society of Pennsylvania, and President of the Pennsylvania chapter of the Wild Flower Preservation Society, wrote A phyto-geographic sketch of extreme southeastern Pennsylvania, published in the 1903 edition of the Bulletin of the Torrey Botanical Club. This article described the Martin Forest (then the property of Mr. J. Howard Lewis, Sr.) as the best example of an old-growth forest remnant in Delaware County.

Stands of mountain laurel, Kalmia latifolia, can be found along the hillside in Martin Forest. photo credit: R. Robert

He also used the Martin Forest tract as one of several models for piecing together the species composition and general appearance of the forests of southeastern Pennsylvania before Europeans settled the area.  The Martin Forest was Harshberger’s model for a “hemlock-mixed oak” forest type.

A half-circle of steep slopes where jagged, massive boulders and cliffs form breaks in a dense cover of oak, eastern hemlock, and mountain laurel in the forest. photo credit: R. Robert

In 2010, Andrew Bunting, former curator of the Scott Arboretum, described the tract as the finest natural forest the College owns. Today, the Martin Forest represents the most intact urban forest fragment in Delaware County, PA.

The tract of land is border by Crum Creek. photo credit: R. Robert

Hikers can find tuliptree and American beech dominating this remnant old-growth forest stand.  Together with boxelder, red maple, sugar maple, bitternut hickory and green ash, a rich understory exists including witchhazel, spicebush and bladdernut, and a lush growth of mostly spring-flowering herbaceous plants. Spring showcases wild ginger, blue cohosh, spring beauty, Dutchman’s breeches, yellow trout lily, Virginia waterleaf, dwarf ginseng, mayapple, skunk-cabbage, bellwort, downy yellow violet, and common blue violet. Sixteen of the tuliptrees are giants, with trunks up to 5 ft. 7.7 in. (172 cm) in diameter and heights over 100 feet (30 m).

Can you find the toad in this image? His camouflage is top notch. photo credit: R. Robert

Bordered on one side by the wild reach of Crum Creek and on the other by a half-circle of steep slopes where jagged, massive boulders and cliffs form breaks in a dense cover of oak, eastern hemlock, and mountain laurel, the Martin Forest is a dramatic landscape to explore this fall.

The post Forgotten Fabulous Fall Color Trails appeared first on Scott Arboretum & Gardens.

One of the Five Best Preserved Areas in the Crum Woods

This February I took a walk through the Wister Forest with Crum Woods Restoration Assistant, Michael Rolli. Of the over 200 acres in the Crum Woods, five unique locations are prominent for their excellent state of preservation: the Wister Forest, Martin Forest, Trillium Slope, Skunk-Cabbage Hollow, and the Southern Red Oak Forest.

The trails through Wister Forest can be steep. photo credit: R. Robert

These sites have been subject to many of the pressures of natural areas such as invasive species competition, deer browsing, trash dumping, and trail use, yet have remained excellent spaces with mature trees, beneficial and endangered species, and wildlife value. Through subsequent blog articles, I will explore each space and share what I’ve learned about its special characteristics, plants, wildlife, and the struggles it faces. I encourage you to visit each beautiful area yourself!

To access the Wister Forest, we entered the woods at the beginning of the Bartram Path near the Water Tower. photo credit: R. Robert

To access the Wister Forest, we entered the woods at the beginning of the Bartram Path near the Water Tower. As we descended the hill, we eventually reached the Wister Forest. This 26.9-acre piece of the forest was designed by John Wister to be composed of only Delaware County plants; however, non-native and invasive plants have crept into the forest over time.

The forest understory today is dominated by our native spicebush (Lindera benzoin) because the deer do not enjoy the spicy taste of this shrub. photo credit: R. Robert

Although a Delaware County forest should have a robust understory of mapleleaf viburnum, arrowwood viburnum, blackhaw viburnum, and pagoda dogwood, the forest today is dominated by our native spicebush (Lindera benzoin) because the deer do not enjoy the spicy taste of this shrub.

In the spring, mayapples dot the forest floor. photo credit: R. Robert

As we descended the hill along the Evans Path, Mike pointed out the biggest northern red oak (Quercus rubra) and slippery elm (Ulmus rubra) in the Crum Woods. Other common woody species in the woods include red maple, black tupelo, dogwood, ash, hickory, tuliptree, cherry, American beeches, and a common pawpaw grove!

Fall color is lovely along this trail. photo credit: R. Robert

As we walked towards Crum Creek, we spotted several stands of mature eastern hemlocks (Tsuga canadensis) growing on a steep slope. The wooly adelgid, an insect which decimates eastern hemlocks, was found in Virginia in 1951 and since has spread quickly through the Eastern United States. Since the invasion of the wooly adelgid, mature stands of hemlocks are extremely rare.

Because the Wister Forest features steep slopes, we noticed erosion near the creek. photo credit: R. Robert

Because the Wister Forest features steep slopes, we noticed erosion near the creek. Michael Rolli has been building brush bars to hold back some of the water that flows quickly down the hill to the creek.

Invasive Japanese knotweed growing along the Crum Creek. photo credit: R. Robert

Along the banks of the creek, we found many invasive plants. In 2011 parts of the forest were cleared to repair the sewer line, which caused the intrusion of several invasive species, including Japanese stilt grass and knotweed. The most immediate goal of reforestation is to increase canopy cover to prevent further germination of invasive plants.

Alligator rock can be found on this stretch of the Crum Woods. photo credit: R. Robert

Following the Valley Walk path, Mike and I walked along the creek and entered the woods again at the Alligator Path. While ascending the slope and making our way back towards the campus, we saw a few invasive ground covers which were planted on the campus and subsequently crept into the Crum Woods; English ivy, Vinca minor, and Japanese pachysandra.

Use this map to explore the Crum Woods. photo credit: R. Robert

Mike also pointed out the largest tree in the Crum Woods (excluding the Martin Forest), a tuliptree! With a diameter of at least 63 inches, this tree is truly massive and stretches well above all the nearby trees.

Early spring is a great time to explore this area as it displays mayapple, trout lily, bloodroot, and Jack-in-the-pulpit. photo credit: R. Robert

The Wister Forest is an interesting part of the Crum Woods with a mixture of cultivated understory plants and naturally occurring trees. Early spring is a great time to explore this area as it will  display mayapple, trout lily, bloodroot, and Jack-in-the-pulpit.

The post A Walk through the Wister Forest appeared first on Scott Arboretum & Gardens.

 

Guest Author: Marissa Lariviere ‘18

Have you ever stumbled across the strange ruins in the Crum Woods? At first glance, these crumbling walls just seem creepy. But don’t run away- this area actually has a long and fascinating history, involving magnificent mansions and dating all the way back to Pennsylvania’s founder, William Penn.

In 1927, Lytlecote was bought by Ward Hinkson and his wife Edith, and renamed Oak Knoll. The Hinksons would go on to construct an elaborate estate over the 32 acres, turning their home into an iconic site in the area. photo credit: Scott Arboretum Archives

Lytlecote

The estate was originally one of three parcels purchased from William Penn in 1681 by a Society of Friends member, Thomas Powell. Centuries later, in 1892, Mrs. James H. Little bought the estate and named it Lytlecote. She built an elite suburban fieldstone mansion on the former farmland, which was described by a contemporary as “one of the most attractive of the many handsome Delaware county estates… massive in its proportions and beautiful in its surroundings.”

A view of the Italian Water Garden from the house. These are the ruins you can find along the trail today. photo credit: Scott Arboretum Archives

Oak Knoll

 In 1927, Lytlecote was bought by Ward Hinkson and his wife Edith, and renamed Oak Knoll. The Hinksons would go on to construct an elaborate estate over the 32 acres, turning their home into an iconic site in the area. This included a swimming pool, a private arboretum, and an Italian Water Garden complete with a fountain. In their gardens, the Hinksons and their six gardeners cultivated boxwood hedges, roses, tree peonies, rhododendrons, and Exbury azaleas, among others. They also planted an abundance of trees, including Norway spruces, white pines, a double-flowering dogwood, golden-flowered fringe trees, a lace leaf maple, and flowering cherry trees. Five greenhouses stood near the house, where the Hinksons grew twelve varieties of orchids commercially. Around 100,000 of these orchid flowers were cut and sold each year.

Five greenhouses stood near the house, where the Hinksons grew twelve varieties of orchids commercially. Around 100,000 of these orchid flowers were cut and sold each year. photo credit: Scott Arboretum Archives

In 1964, the Hinksons sold much of their land to be turned into suburban homes. However, the real demise of Oak Knoll came with the construction of the Blue Route Highway (Interstate 476). The estate was demolished to clear the path for the new road. In preparation, all 73,000 of the Hinksons’ orchids were sold at auction and their greenhouses were dismantled.  By 1967, the Hinksons had moved to a new home in Upper Providence and construction of the Blue Route began. The highway would be completed in 1992.

The trillium that cover the banks of the Crum Woods in the spring are remnants of the Oak Knoll estate. photo credit: R. Robert

Crum Ruins

Today, little remains of the Hinkson’s elaborate estate. However, the ruins of Oak Knoll’s Italian Water Garden can still be found in the Crum Woods. They are now known as “the Crum Ruins,” “the sunken gardens,” or simply “the ruins.” The ruins consist of the stone walls and steps of the water garden, whose stonework is weathered but not seriously damaged. The college has filled in the small central pool with soil to avoid liability. These ruins are a popular destination for hikers, joggers, and bikers on the Leiper-Smedley trail. This paved path, which is over two miles long, runs from the Thomas Leiper House to Smedley Park. Visitors can still see many of the plants that were cultivated at Oak Knoll, including flowering cherries, yews, white pines, a sourwood, a cucumber magnolia, Japanese pachysandra, large-flowered, sessile, and yellow trilliums, and an abundant akebia vine. These ruins are an important part of local history in a beautiful natural setting. For the adventurous hiker, they’re definitely well worth a visit!

_________________________________________________________________________________________________

This article is part of an ongoing column called the Crum Woods Chronicle. The Crum Woods Chronicle will be periodic updates and observations about subjects related to natural history, interesting species found in and around the Crum Woods, and exciting events you can get involved in. My hope is that some of these topics will interest you, strengthen your connection to the Crum Woods, and inspire you to explore your backyard a little more often.

Natural areas do not maintain their character and quality independently, especially when they are heavily used by people and embedded in urban environments. Educating yourself about aspects of the Crum Woods that interest you and understanding how your individual use of the Crum Woods impacts it (and how you can reduce that impact!) are important steps every one of us should take.

“In the end we will conserve only what we love; we will love only what we understand; and we will understand only what we are taught.” –Baba Dioum

The post Off the Beaten Path: History of the Crum Ruins appeared first on Scott Arboretum & Gardens.

Late this February, I explored Skunk Cabbage Hollow with Crum Woods Restoration Assistant, Michael Rolli. Of the over 200 acres in the Crum Woods, five unique locations are prominent for their excellent state of preservation: the Wister Forest, Martin Forest, Trillium Slope, Skunk Cabbage Hollow, and the Southern Red Oak Forest.

This February, the hillside of Wister Garden was covered in winter aconite, Japanese pachysandra, and snowdrops. photo credit: A. Bacon

These sites have been subject to many pressures of natural areas, such as invasive species competition, deer browsing, trash dumping, and trail use, yet have remained excellent spaces with mature trees, beneficial and endangered species, and wildlife value. Through subsequent blog articles, I will explore each space and share what I’ve learned about its special characteristics, plants, wildlife, and the struggles it faces. I encourage you to visit each beautiful area yourself!

Skunk Cabbage Hollow is a 2.7-acre low-lying, swampy area near Crum Creek, easily accessible from the Wister Garden in the southern portion of the Crum Woods. photo credit: R. Robert

Skunk Cabbage Hollow is a 2.7-acre low-lying, swampy area near Crum Creek, easily accessible from the Wister Garden in the southern portion of the Crum Woods. This February, the hillside of Wister Garden was covered in winter aconite, Japanese pachysandra, and snowdrops.

As is typical of many low-lying areas in early spring, we saw the heart-shaped leaves of the invasive lesser celandine leaves carpeting the ground. photo credit: R. Robert

Although these species have ornamental value, they have crept into Skunk Cabbage Hollow and are currently battling for space with our native groundcovers. As is typical of many low-lying areas in early spring, we saw the heart-shaped leaves of the invasive lesser celandine leaves emerging. Gardeners also struggle to eradicate invasive grapevines, porcelainberry, and privet within Skunk Cabbage Hollow.

Despite its struggles with aggressive plants, Skunk Cabbage Hollow remains an invaluable place for wildlife. Because of the plant species that thrive here and the wetland conditions in certain areas, Skunk Cabbage Hollow provides far more wildlife services than many other locations in the Crum Woods.

Mallards are often seen swimming in the shallow waters near the bank of Crum Creek. photo credit: R. Robert

Skunk Cabbage Hollow has a robust shrub and herbaceous layer, which is especially beneficial for wildlife searching for cover from predators and shelter for their young. Mallards are often seen swimming in the shallow waters near the bank of Crum Creek. Other bird species also stop by Skunk Cabbage Hollow along their migration route because of the excellent shelter, water, and food it provides.

Almost immediately apparent after reaching the creek were the unique flowers of the Skunk Cabbage (Symplocarpus foetidus) which emerge before the skunk-smelling leaves. photo credit: A. Bacon

Almost immediately apparent after reaching the creek were the unique flowers of the Skunk Cabbage (Symplocarpus foetidus) which emerge before the skunk-smelling leaves. The flowers are composed of a modified leaf called a spathe that wraps around the fragile spadix. The spadix is an ovular yellow-green modified stem containing dozens of small flowers.

This remarkable native flower can warm itself while actively flowering, thereby melting the snow that surrounds it, and maintain its temperature at 36° F above the ambient temperature. The spathe of this plant varies greatly and can be any combination of red, purple, green, and yellow, with an interesting spotted pattern.

The thorned honeylocust evolved these thorns to deter megafauna (large animals, many of which are now extinct) which would eat its bark and damage the tree while reaching for the large seedpods. photo credit: A. Bacon

Another fascinating plant in Skunk Cabbage Hollow is the thorned honeylocust (Gleditsia triacanthos). In all my horticultural experience, I have never seen a thorned species to rival this tree, with thorns sometimes reaching a length greater than 8 inches. The thorned honeylocust evolved these thorns to deter megafauna (large animals, many of which are now extinct) which would eat its bark and damage the tree while reaching for the large seedpods. Although many of these megafauna disappeared as a result of early human interactions, the thorned honeylocust has kept its thorns.

Mike hypothesizes that the thorned honeylocust is another of the many indications of a American Indian settlement in the Crum Woods. It is well-documented that Ockanickon people had seasonal settlements along the Crum Creek, and a paper published last year that showed that almost every stand of honeylocust in the southern Appalachians corresponds to a historic American Indian settlement. American Indians created weapons and tools using the thorns, and may have planted this tree in Skunk Cabbage Hollow for their use.

Cephalanthus occidentalis seed heads are visible in the winter. photo credit: J. Coceano

Several other species in Skunk Cabbage Hollow are balsam poplars (Populus balsamifera), black willow (Salix nigra), boxelder (Acer negundo), silky dogwood (Cornus amomum), red maple (Acer rubrum), white oak, (Quercus alba), green ash (Fraxinus pennsylvanica), and buttonbush (Cephalanthus occidentalis).

Another specie found in the Skunk Cabbage Hollow is Acer rubrum; seen here in fall color. photo credit: R. Robert

The three mature trees of balsam poplar are the only known stand in Delaware County. It might be the rarest tree in the Crum Woods.

Skunk Cabbage Hollow is the only location in the Crum Woods to find buttonbush and green ash. These plants are typical in wet areas.

Skunk cabbage serves as a groundcover. photo credit: R. Robert

Groundcovers and small herbaceous plants in Skunk Cabbage Hollow include rushes, sedges, Joe Pye weed, sensitive fern, smartweed, and, of course, skunk cabbage. Additionally, adjacent to Skunk Cabbage Hollow, Mike found an umbrella magnolia (Magnolia tripetalata) which is endangered in Pennsylvania, evidence of this incredibly important ecosystem.

Piles of the invasive privet can be seen behind Gardener Adam Glas while he plants native species in the hollow. photo credit: R. Robert

In the past three years Arboretum volunteers have spent many sessions removing border privet (Ligustrum obtusifolium) and other foreign shrubs.  You can see the piles of privet carnage scattered about. About 500 trees and shrubs have been planted in the past two spring plant-outs, including:

Volunteers Ted Patterson and Ann Ainsworth planting trees during spring plant out in the Crum Woods. photo credit: R. Robert

Asimina triloba (pawpaw)

Prunus serotina (black cherry)

Cephalanthus occidentalis (buttonbush)

Chionanthus virginicus (white fringe tree)

Clethra alnifolia (sweet pepperbush)

Ilex verticillata (winterberry)

Nyssa sylvatica (black tupelo)

Salix exigua (coyote willow)

Salix nigra (black willow)

Salix sericea (silky willow)

Sambucus nigra ssp. canadensis (American elder)

Take some time this spring to explore this unique ecosystem and interact with some of our own native flora and fauna. photo credit: R. Robert

Take some time this spring to explore this unique ecosystem and interact with some of our own native flora and fauna. See if you can find these ecological gems for yourself.

The post Unique Ecosystem of Skunk Cabbage Hollow appeared first on Scott Arboretum & Gardens.

The original Crumhenge had a graveyard-like quality with thin, tall rectangular rocks standing upright. photo credit: R. Robert

The history and purpose of Stonehenge is still something of a mystery, but historians are sure the stones were not arbitrarily arranged. As the UNESCO World Heritage site notes about Stonehenge: “The design, position, and interrelationship of the monuments and sites are evidence of a wealthy and highly organised prehistoric society able to impose its concepts on the environment. An outstanding example is the alignment of Stonehenge Avenue (probably a processional route) and Stonehenge stone circle on the axis of the midsummer sunrise and midwinter sunset, indicating their ceremonial and astronomical character.”

This shot from a flood in 2007 shows the Crumhenge above water. photo credit: R. Manduca

Although Crumhenge does not have a mysterious underlying purpose, it is still a fascinating spectacle, especially when standing on the hilltop overlooking the meadow. Steve Wheaton, who was the Director of Grounds at the time, installed Crumhenge in the 1980s. The original Crumhenge had a graveyard-like quality with thin, tall rectangular rocks standing upright and four boulders indicating the four compass directions. Around these rocks marking north, south, east and west, several other rocks were arranged to form a circle.

Logs can been seen  stacked in the Crumhenge in preparation for bonfire. photo credit: R. Robert

Crumhenge has existed primarily for the enjoyment of Swarthmore College students, who often use the fire pit for bonfires. Unfortunately, due to the SEPTA trestle construction, Crumhenge was deconstructed in 2015 so the boulders would not be damaged.

The Crumhenge became a construction site in 2016. photo credit: R. Robert

This fall, the original Crumhenge was reconstructed with all the boulders lying flat on the ground. Two concentric circles replaced the original circle; one hugs the fire pit for close seating around the fire, and the other rests several paces outwards. The original stones were used, but additional stones from the Crum Woods were added to create the final arrangement.

This fall, the original Crumhenge was reconstructed with all the boulders lying flat on the ground. photo credit: A. Bacon

Jeff Jabco, current Director of Grounds, asked that the pathways leading to the center of the arrangement be aligned with the compass points. Of course, Jeff couldn’t help but add with a grin, “The new Crum Henge was laid out and installed during a full moon utilizing the principles of Feng Shui.”

You can reuse and redesign parts of your garden by moving plants and hardscaping elements around to add an entirely different aesthetic to the garden. Landscapes are not set in stone; consider refreshing a tired corner of your garden as a New Year resolution.

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This article is part of an ongoing column called the Crum Woods Chronicle. The Crum Woods Chronicle will be periodic updates and observations about subjects related to natural history, interesting species found in and around the Crum Woods, and exciting events you can get involved in. My hope is that some of these topics will interest you, strengthen your connection to the Crum Woods, and inspire you to explore your backyard a little more often.

Natural areas do not maintain their character and quality independently, especially when they are heavily used by people and embedded in urban environments. Educating yourself about aspects of the Crum Woods that interest you and understanding how your individual use of the Crum Woods impacts it (and how you can reduce that impact!) are important steps every one of us should take.

“In the end we will conserve only what we love; we will love only what we understand; and we will understand only what we are taught.” –Baba Dioum

The post Return of Crumhenge appeared first on Scott Arboretum & Gardens.

At 2.55 acres, the tulip tree-beech-maple forest planting is the largest restoration community with woody plants in the mix. photo credit: R. Robert

At 2.55 acres, the tulip tree-beech-maple forest planting is the largest restoration community with woody plants in the mix. As the name implies, this community consists predominantly of Acer rubrum, Fagus grandifolia, and Liriodendron tulipifera. The understory shrubs consist of Hamamelis virginiana (witch hazel), Amelanchier canadensis (serviceberry), and Crataegus crus-galli (cockspur hawthorn).

A tulip tree-beech-maple forest typically occurs in fairly, deep but not strongly acidic soil at a mid to lower slope position. If not over browsed, this community supports a diverse herbaceous layer with plants including spring ephemerals such as common jack-in-the-pulpit, mayapple, yellow trout lily, large-flowered trillium, and wild ginger.

This diversity also supports a variety of wildlife: short-tailed shrew, white-footed mouse, long-tailed weasel, and eastern chipmunk. One can also find red-backed salamander, gray treefrog, American toad, black rat snake, and spicebush swallowtail butterfly. Nesting habitat for many forest birds such as wood thrush, scarlet tanager, rose-breasted grosbeak, red-eyed vireo, ovenbird, hooded warbler, American redstart, cerulean warbler, barred owl, and pileated woodpecker can found in this forest community.

The yellow color of Liriodendron tulipifera adds fabulous autumn splendor in the space this time of year. photo credit: R. Robert

The Arboretum uses these native canopies – tulip trees, beeches, and red maples – through the campus as great garden plants too. Tulip trees, Liriodendron tulipifera, tower over the Scott Outdoor Amphitheater. Its stick-straight habit makes it ideal for creating a tall canopy with dappled shade for visitors and nesting habitat for birds. The yellow color adds fabulous autumn splendor in the space this time of year. The spring flowers attracts butterflies and hummingbirds.

One of the most commonplace native trees, red maple do not disappoint when it comes to fall color. photo credit: R. Robert

Red maples, Acer rubrum, are great deciduous trees for your garden. One of the most commonplace native trees, red maple do not disappoint when it comes to fall color. On campus we have several striking cultivars including A.rubrum ‘Brandywine’ and A. rubrum ‘Red Sunset’, both selected for their brilliant fall color. This canopy also provide cover for screech owls and pileated woodpeckers while common flickers nest in the cavities.

The dark green toothed leaves of Fagus grandifolia brighten to a golden bronze in the fall. photo credit: R. Robert

Finally the American beech tree, Fagus grandifolia, is a large deciduous tree known for its smooth, grey bark. These specimen trees have a dramatic presence in the landscape with low branching and mature trunks of 2- to 3- feet in diameter. The dark green toothed leaves brighten to a golden bronze in the fall. The beech nut, which ripens in the fall, is a great food source for birds and mammals like mice, squirrels,chipmunks, black bear, deer, foxes, ruffed grouse, ducks, and bluejays.

I invite you to visit the newly open area around the SEPTA Viaduct to see the restoration and watch it mature. photo credit: R. Robert

I invite you to visit the newly open area around the SEPTA Viaduct to see the restoration and watch it mature. I also invite to you find the young plants we have planted and compare them to the matures ones that have been gracing the campus for generations. Consider planting native trees in your own garden to help ecosystem as a whole.

____________________________________________________________________________________________________________________________

This article is part of an ongoing column called the Crum Woods Chronicle. The Crum Woods Chronicle will be periodic updates and observations about subjects related to natural history, interesting species found in and around the Crum Woods, and exciting events you can get involved in. My hope is that some of these topics will interest you, strengthen your connection to the Crum Woods, and inspire you to explore your backyard a little more often.

Natural areas do not maintain their character and quality independently, especially when they are heavily used by people and embedded in urban environments. Educating yourself about aspects of the Crum Woods that interest you and understanding how your individual use of the Crum Woods impacts it (and how you can reduce that impact!) are important steps every one of us should take.

“In the end we will conserve only what we love; we will love only what we understand; and we will understand only what we are taught.” –Baba Dioum

The post Restoring the Crum Woods appeared first on Scott Arboretum & Gardens.

As we reach fall foliage peak here in the Delaware Valley, it is a great time to take a walk in our native woodland the Crum Woods. While exploring the trails, you may discover the native gem Chimaphila maculata, spotted wintergreen, tucked under the colorful fallen leaves.

This small evergreen perennial is conspicuous during this time of year with its white and green mottled leaves against the yellows, reds, and browns of fall. This delicate groundcover is often found in dry oak-heath forests.

Here you can see the brown capsules that persist until the next flowering season. photo credit: R. Robert

Nodding, fragrant white to pink flowers bloom in small clusters during the summer months. They ripen into brown capsules that persist until the next flowering season. In addition to seed propagation, this slow-grower reproduces with underground runners.

As you hike, explore the forest floor native gems like Chimaphila maculata. Consider adding this delightful  groundcover to your shade garden.

______________________________________________________________________________________

This article is part of an ongoing column called the Crum Woods Chronicle. The Crum Woods Chronicle will be periodic updates and observations about subjects related to natural history, interesting species found in and around the Crum Woods, and exciting events you can get involved in. My hope is that some of these topics will interest you, strengthen your connection to the Crum Woods, and inspire you to explore your backyard a little more often.

Natural areas do not maintain their character and quality independently, especially when they are heavily used by people and embedded in urban environments. Educating yourself about aspects of the Crum Woods that interest you and understanding how your individual use of the Crum Woods impacts it (and how you can reduce that impact!) are important steps every one of us should take.

“In the end we will conserve only what we love; we will love only what we understand; and we will understand only what we are taught.” –Baba Dioum

The post Chimaphila maculata appeared first on Scott Arboretum & Gardens.