Magnolias and Tuliptrees (Magnoliids) – LIFE IN THE LOWER SUSQUEHANNA RIVER WATERSHED

May 14, 2023May 14, 2023

Mother’s Day Flowers

Let’s have a look at some of the magnificent native wildflowers blooming on this Mother’s Day in forests and thickets throughout the Lower Susquehanna River Watershed.

Rue Anemone (Thalictrum thalictroides) is a fragile little wildflower of open woods.

The Blackhaw (Viburnum prunifolium) is a shrub of thickets and forest borders. The flower clusters mature into an abundance of berries relished by birds and other wildlife.

A large Black Cherry tree adorned in white blossoms can be pleasing to the eye and very beneficial for pollinating insects.

The Common Pawpaw is a small tree of damp well-drained soils. Where conditions are ideal, it may form clonal colonies in the forest understory. The deep maroon blooms mature into banana-like fruits, hence its alternate common name “Custard Apple”.

The Mayapple or Mandrake (Podophyllum peltatum) commonly blankets the forest floor. It, like other ephemeral wildflowers, is vulnerable to invasions by non-native shrubs that leaf out earlier in spring than native species and rob them of sunlight during their already abbreviated growing season.

Aren’t they spectacular?

Why not take a stroll to have a look at these and other plants you can find growing along a nearby woodland trail? You could check out some place new and get a little exercise too!

If you go, please tread lightly, take your camera, mind your manners, and…

March 3, 2023March 10, 2023

Plantings for Wet Lowlands

This linear grove of mature trees, many of them nearly one hundred years old, is comprised of a mix of native White Oaks (Quercus alba) and Swamp White Oaks (Quercus bicolor).

Imagine a planting like this along that section of stream you’re mowing or grazing right now. The Swamp White Oak in particular thrives in wet soils and is available now for just a couple of bucks per tree from several of the lower Susquehanna’s County Conservation District Tree Sales. These and other trees and shrubs planted along creeks and rivers to create a riparian buffer help reduce sediment and nutrient pollution. In addition, these vegetated borders protect against soil erosion, they provide shade to otherwise sun-scorched waters, and they provide essential wildlife habitat. What’s not to love?

The following native species make great companions for Swamp White Oaks in a lowland setting and are available at bargain prices from one or more of the County Conservation District Tree Sales now underway…

The Red Maple is an ideal tree for a stream buffer project. They do so well that you should limit them to 10% or less of the plants in your project so that they don’t overwhelm slower-growing species.

The River Birch (Betula nigra) is a multi-trunked tree of lowlands. Large specimens with arching trunks help shade waterways and provide a source of falling insects for surface-feeding fish. Its peeling bark is a distinctive feature.

The Common Winterberry with its showy red winter-time fruit is a slow-growing shrub of wet soils. Only female specimens of this deciduous holly produce berries, so you need to plant a bunch to make sure you have both genders for successful pollination.

American Robins feeding on Common Winterberry. — An American Robin feeding on Common Winterberry.

Common Spicebush is a shrub of moist lowland soils. It is the host plant for the Spicebush Swallowtail butterfly and produces small red berries for birds and other wildlife. Plant it widely among taller trees to provide native vegetation in the understory of your forest.

Common Spicebush foliage and berries. — Common Spicebush foliage and berries in the shade beneath a canopy of tall trees.

The Buttonbush is a shrub of wet soils. It produces a round flower cluster, followed by this globular seed cluster.

And don’t forget the Eastern Sycamore, the giant of the lowlands. At maturity, the white-and-tan-colored bark on massive specimens makes them a spectacular sight along stream courses and river shores. Birds ranging from owls, eagles, and herons to smaller species including the Yellow-throated Warbler rely upon them for nesting sites.

Yellow-crowned Night Herons Nesting in an Eastern Sycamore — Yellow-crowned Night Herons, an endangered species in Pennsylvania, nesting in an Eastern Sycamore.

So don’t mow, do something positive and plant a buffer!

Act now to order your plants because deadlines are approaching fast. For links to the County Conservation District Tree Sales in the Lower Susquehanna River Watershed, see our February 18th post.

September 13, 2017September 4, 2019

Living in the Shadows

They get a touch of it here, and a sparkle or two there. Maybe, for a couple of hours each day, the glorious life-giving glow of the sun finds an opening in the canopy to warm and nourish their leaves, then the rays of light creep away across the forest floor, and it’s shade for the remainder of the day.

The flowering plants which thrive in the understory of the Riparian Woodlands often escape much notice. They gather only a fraction of the daylight collected by species growing in full exposure to the sun. Yet, by season’s end, many produce showy flowers or nourishing fruits of great import to wildlife. While light may be sparingly rationed through the leaves of the tall trees overhead, moisture is nearly always assured in the damp soils of the riverside forest. For these plants, growth is slow, but continuous. And now, it’s show time.

So let’s take a late-summer stroll through the Riparian Woodlands of Conewago Falls, minus the face full of cobwebs, and have a look at some of the strikingly beautiful plants found living in the shadows.

Oxeye *(Heliopsis helianthoides)* is common on the interior and along the edges of Riparian Woodland. Specimens in deep shade flower less profusely and average less than half the height of the five feet tall inhabitants of edge environs.

Pale Touch-Me-Not *(Impatiens pallida)* is one of two species of native *Impatiens* found in the river floodplain. Both are known as Jewelweed. The stems and leaves of the indigenous Impatiens retain a great quantity of water, so life in filtered sunlight is essential to prevent desiccation. Contrary to popular folklore, extracts of Jewelweed plants are not effective treatments of Poison Ivy *(Toxicodendron radicans)* contact dermatitis.

Spotted Touch-Me-Not *(Impatiens capensis)* is typically found in wetter soil than *I. pallida*. Both Jewelweeds develop popping capsules which help to distribute the seeds of these annual wildflowers. “Touch Me Not”, or you’ll be wearing tiny seeds.

Green-headed Coneflower *(Rudbeckia laciniata)* grows to heights of eight feet in full sun, hence its alternate common name, Tall Coneflower. In deep shade, it may not exceed two feet in height. Floodplains are the prime domain of this perennial.

Wingstem *(Verbesina alternifolia)* normally flowers no earlier than late August. The bases of the leaves are continued onto the stem of the plant to form wings which extend downward along its length. This wildflower tolerates shade, but flowers more profusely along the woodland edge.

Great Lobelia *(Lobelia siphilitica),* or Great Blue Lobelia, is a magnificent wetland and moist woodland wildflower, usually attaining three feet in height and adorned with a plant-topping spike of blossoms. Invasive Japanese Stiltgrass *(Microstegium vimineum)* can be seen here competing with this plant, resulting in a shorter, less productive Lobelia. Stiltgrass was not found in the Susquehanna River floodplain at Conewago Falls until sometime after 1997. It has spread to all areas of woodland shade, its tiny seeds being blown and translocated along roads, mowed lots, trails, and streams to quickly colonize and overtake new ground.

American Bladdernut *(Staphylea trifolia),* a shrub of shaded woods, develops inflated capsules which easily float away during high water to distribute the seeds contained inside.

Buttonbush *(Cephalanthus occidentalis)* is a shrub of wet soils which produces a strange spherical flower, followed by this globular seed cluster.

Common Pawpaw (Asimina triloba) is a colony-forming small tree which produces a fleshy fruit. It is the host plant for the caterpillars of the Zebra Swallowtail. The plant and the butterfly approach the northern limit of their geographic range at Conewago Falls.

Common Spicebush *(Lindera benzoin)* is a widespread understory shrub in wet floodplain soils. It is the host plant for the caterpillars of the Spicebush Swallowtail *(Papilio troilus)*.

Sweet Autumn Virgin’s Bower *(Clematis terniflora)* is an escape from cultivation which has recently naturalized in the edge areas of the Conewago Falls Riparian Woodlands. This vine is very showy when flowering and producing seed, but can be detrimental to some of the understory shrubs upon which it tends to climb.

SOURCES

Long, David; Ballentine, Noel H.; and Marks, James G., Jr. 1997. Treatment of Poison Ivy/Oak Allergic Contact Dermatitis With an Extract of Jewelweed. American Journal of Contact Dermatitis. 8(3): pp. 150-153.

Newcomb, Lawrence. 1977. Newcomb’s Wildflower Guide. Little, Brown and Company. Boston, Massachusetts.

August 7, 2017September 4, 2019

Fussy Eaters

She ate only toaster pastries…that’s it…nothing else. Every now and then, on special occasions, when a big dinner was served, she’d have a small helping of mashed potatoes, no gravy, just plain, thank you. She received all her nutrition from several meals a week of macaroni and cheese assembled from processed ingredients found in a cardboard box. It contains eight essential vitamins and minerals, don’t you know? You remember her, don’t you?

Adult female butterflies must lay their eggs where the hatched larvae will promptly find the precise food needed to fuel their growth. These caterpillars are fussy eaters, with some able to feed upon only one particular species or genus of plant to grow through the five stages, the instars, of larval life. The energy for their fifth molt into a pupa, known as a chrysalis, and metamorphosis into an adult butterfly requires mass consumption of the required plant matter. Their life cycle causes most butterflies to be very habitat specific. These splendid insects may visit the urban or suburban garden as adults to feed on nectar plants, however, successful reproduction relies upon environs which include suitable, thriving, pesticide-free host plants for the caterpillars. Their survival depends upon more than the vegetation surrounding the typical lawn will provide.

The Monarch (Danaus plexippus), a butterfly familiar in North America for its conspicuous autumn migrations to forests in Mexico, uses the milkweeds (Asclepias) almost exclusively as a host plant. Here at Conewago Falls, wetlands with Swamp Milkweed (Asclepias incarnata) and unsprayed clearings with Common Milkweed (A. syriaca) are essential to the successful reproduction of the species. Human disturbance, including liberal use of herbicides, and invasive plant species can diminish the biomass of the Monarch’s favored nourishment, thus reducing significantly the abundance of the migratory late-season generation.

Monarch caterpillar after a fourth molt. The fifth instar feeding on Swamp Milkweed.

A fifth molt begets the Monarch pupa, the chrysalis, from which the showy adult butterfly will emerge.

Adult Monarch feeding on Goldenrod *(Solidago)* nectar.

Butterflies are good indicators of the ecological health of a given environment. A diversity of butterfly species in a given area requires a wide array of mostly indigenous plants to provide food for reproduction. Let’s have a look at some of the species seen around Conewago Falls this week…