A Visit to a Beaver Pond

To pass the afternoon, we sat quietly along the edge of a pond created recently by North American Beavers (Castor canadensis).  They first constructed their dam on this small stream about five years ago.  Since then, a flourishing wetland has become established.  Have a look.

A Beaver Pond
Vegetation surrounding the inundated floodplain helps sequester nutrients and sediments to purify the water while also providing excellent wildlife habitat.
A beaver lodge.
The beaver lodge was built among shrubs growing in shallow water in the middle of the pond.
Woolgrass in a beaver pond.
Woolgrass (Scirpus cyperinus) is a bulrush that thrives as an emergent and as a terrestrial plant in moist soils bordering the pond.
A male Common Whitetail dragonfly keeping watch over his territory.
A male Common Whitetail dragonfly keeping watch over his territory.
A Twelve-spotted Skimmer perched on Soft Rush.
A Twelve-spotted Skimmer perched on Soft Rush.
A Blue Dasher dragonfly seizing a Fall Field Cricket (Gryllus pennsylvanicus).
A Blue Dasher dragonfly seizing a Fall Field Cricket (Gryllus pennsylvanicus).
A Spicebush Swallowtail visiting Cardinal Flower.
A Spicebush Swallowtail visiting a Cardinal Flower.
Green Heron
A Green Heron looking for small fish, crayfish, frogs, and tadpoles.
A Green Heron stalks potential prey.
The Green Heron stalking potential prey.
A Wood Duck feeding on Lesser Duckweed.
A Wood Duck feeding on the tiny floating plant known as Lesser Duckweed (Lemna minor).
A Least Sandpiper feeding along the muddy edge of a beaver pond.
A Least Sandpiper poking at small invertebrates along the muddy edge of the beaver pond.
Solitary Sandpiper
A Solitary Sandpiper.
A Solitary Sandpiper testing the waters for proper feeding depth.
A Solitary Sandpiper testing the waters for proper feeding depth.
Pectoral Sandpiper
A Pectoral Sandpiper searches for its next morsel of sustenance.
A Sora rail in a beaver pond.
The Sora (Porzana carolina) is a seldom seen rail of marshlands including those created by North American Beavers.  Common Cattails, sedges, and rushes provide these chicken-shaped wetland birds with nesting and loafing cover.

Isn’t that amazing?  North American Beavers build and maintain what human engineers struggle to master—dams and ponds that reduce pollution, allow fish passage, and support self-sustaining ecosystems.  Want to clean up the streams and floodplains of your local watershed?  Let the beavers do the job!

One of Nature’s Finest: The Cardinal Flower

It may be one of the most treasured plants among native landscape gardeners.  The Cardinal Flower (Lobelia cardinalis) blooms in August each year with a startling blaze of red color that, believe it or not, will sometimes be overlooked in the wild.

Cardinal Flower on a Stream
Cardinal Flower is most often found in wet soil along forested bodies of water.  The blooms of this shade-loving species may go unnoticed until rays of sunshine penetrate the canopy to strike their brilliant red petals.

The Cardinal Flower grows in wetlands as well as in a variety of moist soils along streams, rivers, lakes, and ponds.  Shady locations with short periods of bright sun each day seem to be favored for an abundance of color.

Cardinal Flower and Great Blue Lobelia
Cardinal Flower in bloom in a riparian forest along the Susquehanna.  To its right is its close relative, Great Lobelia, a plant sometimes known as Great Blue Lobelia or Blue Cardinal Flower.
Cardinal Flower in a wet bottomland woods.
Cardinal Flower in a wet bottomland woods.
The Cardinal Flower can find favorable growing conditions along stream, river and lake shores.
The Cardinal Flower can find favorable growing conditions along stream, river, and lake shores.  Even though they are perennial plants, their presence along such waters often seems temporary.  Changing conditions cause them to suddenly disappear from known locations, then sometimes reappear at the same place or elsewhere nearby.  Some of this phenomenon may be due to the fact that stressed plants can fail to bloom, so they easily escape notice.  When producing flowers during favorable years, the plants seem to mysteriously return.
Cardinal Flowers along a wave-swept shoreline light up the greenery of erosion-controlling riparian vegetation with glowing red color.
Cardinal Flowers along a wave-swept shoreline light up the greenery of erosion-controlling riparian vegetation with glowing red color.

The Cardinal Flower can be an ideal plant for attracting hummingbirds, bees, butterflies, and other late-summer pollinators.  It grows well in damp ground, especially in rain gardens and along the edges streams, garden ponds, and stormwater retention pools.  If you’re looking to add Cardinal Flower to your landscape, you need first to…

REMEMBER the CARDINAL RULE…

Cardinal Flower plants are available at many nurseries that carry native species of garden and/or pond plants.  Numerous online suppliers offer seed for growing your own Cardinal Flowers.  Some sell potted plants as well.  A new option is to grow Cardinal Flowers from tissue cultures.  Tissue-cultured plants are raised in laboratory media, so the pitfalls of disease and hitchhikers like invasive insects and snails are eliminated.  These plants are available through the aquarium trade from most chain pet stores.  Though meant to be planted as submerged aquatics in fish tank substrate, we’ve reared the tissue-cultured stock indoors as emergent plants in sandy soil and shallow water through the winter and early spring.  When it warms up, we transplant them into the edges of the outdoor ponds to naturalize.  As a habit, we always grow some Cardinal Flower plants in the fish tanks to take up the nitrates in the water and to provide a continuous supply of cuttings for starting more emergent stock for outdoor use.

Tissue culture Cardinal Flower being grown as a submerged aquatic in a fish aquarium.
A tissue-cultured Cardinal Flower rooted in sandy substrate and being grown as a submerged aquatic plant in a fish tank.  Cuttings from this plant will be used to grow emergent specimens in shallow water for transplanting outdoors around the garden pond.
Cardinal Flower from Tissue Culture
A Cardinal Flower grown from an aquarium store tissue culture blooms in the pond at susquehannawildlife.net headquarters.
Cardinal Flower blooming in November.
Grown as an emergent, Cardinal Flower may bloom very late in the season.  This tissue-cultured specimen in the headquarters pond was photographed in early November, 2022.

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.