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.

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

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