Sesbania vesicaria (Bagpod) at Falls Lake, North Carolina

Primarily a Coastal Plain plant that thrives in ditches and wet, disturbed areas, Bagpod – Sesbania vesicaria – is a relative newcomer to the Falls Lake area. Populations of this tall, gangly, woody annual have gradually been moving inland and northward, establishing colonies in a few places along the shoreline of Falls Lake and even appearing along a small suburban greenway.

Sesbania vesicaria Bagpod

Sesbania vesicaria
Bagpod

Sesbania vesicaria Bagpod

Sesbania vesicaria
Bagpod

Sesbania vesicaria Bagpod

Sesbania vesicaria
Bagpod

Individual plants can be quite large, up to 12 feet high, and have a stark, skeletal appearance.

Sesbania vesicaria Bagpod

Sesbania vesicaria
Bagpod

Bagpods are legumes, members of the bean family (Fabaceae), whose common name results from the large, dangling pods that usually contain 2 seeds each. Mature pods have two distinct layers protecting the seeds. A tough outer layer protects a thin, flexible inner layer that contains the seeds. The inner layer looks a lot like a soft, pale sock and can easily be removed from the outer layer.

IMG_0087

Tough, Outer Layer of the Seed Pod of Sesbania vesicaria

Outer Layer of Seed Pod Open to Reveal the Soft Inner Layer of the Pod  Sesbania vesicaria

Outer Layer of Seed Pod Opened to Reveal the Soft Inner Layer
Sesbania vesicaria

The following, closer view shows the soft, inner layer inside the tough, outer layer.  The shadow of the seed can be seen in the top chamber of the inner layer.

Close-Up of Outer and Inner Layers of Pod Sesbania vesicaria

Close-Up of Outer and Inner Layers of Pod
Sesbania vesicaria

The soft, inner layer of the pod can be easily removed from the outer layer.

Soft, Inner Layer of Seed Pod Sesbania vesicaria

Soft, Inner Layer of Seed Pod
Sesbania vesicaria

Seeds Sesbania vesicaria

Seeds
Sesbania vesicaria

A few years ago, I picked and planted 7 seeds from a dry Bagpod plant in early winter, not knowing at that time what the plant was. No seeds germinated the following spring, but a year after that, in early April, 3 out of the 7 seeds germinated.

Sesbania vesicaria seedlings have a fascinating early development. The cotyledon leaves are smooth and thick, and are rectangular with rounded ends, like an oar. The first true leaf is also smooth and thick, but a little larger and more ovate. The second true leaf, which comes in opposite the first, is a compound leaf with the leaflets opposite each other.  This compound leaf pattern is sometimes called even pinnately compound. Each new leaf after that is alternate and compound, with 8 to 40 opposing leaflets.
IMG_7018 Sesbania vesicaria

Sesbania vesicaria Young Plant in Sand at Water's Edge

Sesbania vesicaria
Young Plant in Sand at Water’s Edge

Flowers appear in the leaf axils in mid-summer to early fall and are yellow , but can be tinged with red or orange. So far, the flowers in the Falls Lake area have been yellow and not tinged with other colors.

Sesbania vesicaria Flower

Sesbania vesicaria
Flower

On the South Carolina Coastal Plain, Sesbania vesicaria can occur in huge numbers. In the summer and fall, the ditches of the Bear Island and Donnelley Wildlife Management Areas are full of large numbers of these plants, stretching for miles. They are sometimes found  mixed with populations of Sesbania herbacea, a similar plant whose seed pods are long, thin and curving.

Herb Amyx

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Late Fall Germination of Diamorpha smallii (Elf Orpine)

It is early on a bright, sunny morning in late November on the granitic flatrocks of the Mitchell Mill State Natural Area. Following a hard overnight freeze, sheets of ice cover the depression pools formed on the surface of the flatrock.   From a standing position, the tiny seedlings of Elf Orpine (Diamorpha smallii) look like small, red pebbles .

Diamorpha smallii

Diamorpha smallii

The next two photos are taken from a few inches above the ice, giving a clearer view of the developing seedlings of this remarkable annual, which is now beginning a new life cycle.

Diamorpha smallii -  Elf Orpine

Diamorpha smallii -
Elf Orpine

Diamorpha smallii -  Elf Orpine

Diamorpha smallii -
Elf Orpine

A high magnification close-up helps to illustrate the earliest stages of germination.  In the shot below, the red pointer on the right indicates the first embryonic leaves.  The red line on the left points to the buds of the first true leaves.  Three other seedlings can be seen in the 4 leaf stage, as the rosettes begin to form.  Growth will continue during periods of warmer weather, but at a very slow pace.

Close View of Diamorpha smallii in Early Germination Stages

Close View of Diamorpha smallii in Early Germination Stages

The depression pools are a harsh environment, but they do protect the tiny seedlings from competition with other plants.

Just off the edge of the granite flatrocks,  a plant that appears to be a ground cover can be seen.

Ligustrum sinense -  Chinese Privet

Ligustrum sinense -
Chinese Privet

But a closer look reveals the groundcover is actually formed by young Ligustrum sinense – Chinese Privet – a serious invasive problem at Mitchell Mill.

Ligustrum sinense -  Chinese Privet Seedlings

Ligustrum sinense -
Chinese Privet

This year, biologists in the Natural Resources Program of the North Carolina Department of Environment and Natural Resources implemented a pilot program to control or eliminate Chinese Privet at Mitchell Mill.   Fortunately the pilot program went extremely well.  Help is on the way to controlling this invasive plant, which currently dominates many areas of  the Mitchell Mill S. N. A.

Herb Amyx

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The November Lake Shore – Part 2

The November lake shore community at the Falls Lake State Recreation Area is alive with the final blooms of a wide assortment of flowering plants.  One thing they have in common is their unusually small size, attributed primarily to their late germination and rush to bloom before heavy freezes.  Keeping the plants company are a very large number of Cricket Frogs enjoying the mid day sun during the chilly  temperatures.

Cricket Frog

Cricket Frog

Lurking just behind the seedling Eryngium prostratum (featured in the previous blog) is Ludwigia palustris – Marsh Seedbox -one of the 3 species of Ludwigia growing together along the shore.  Although Ludwigia palustris is a native, it is still considered an invasive and can be a problem in some parts of the lake.  The recumbent, trailing growth pattern gives the impression of the plants flowing across the ground.  The tiny flowers at the leaf axils are difficult to see; a red arrow points to one flower in the following photo.

Ludwigia palustris

Ludwigia palustris

A couple of closer looks at the tiny flowers.

Ludwigia palustris Flower

Ludwigia palustris
Flower

IMG_1085a

Diminutive Bidens frondosa – Common or Devil’s Beggarticks – are blooming here as well.  These native annuals are commonly 1 to 3 feet tall, but here they are 4 to 8 inches tall in bloom.

Bidens frondosa Common Beggarticks

Bidens frondosa
Common Beggarticks

Bidens frondosa Common Beggarticks

Bidens frondosa
Common Beggarticks

Occasionally tiny yellow Ludwigia blooms can be seen among the E. prostratum.  Although Ludwigia alternifolia – Seedbox – is the commonest of this genus along the shore, the blooming plants are actually Ludwigia decurrens – Wingleaf Primrose Willow.   A red arrow points to a seedbox on one of the plants.

Ludwigia decurrens Wingleaf Primrose-willow

Ludwigia decurrens
Wingleaf Primrose-willow

The distinctive shape and length of the seedbox and the winged stems help to identify these plants as Ludwigia decurrens.

Ludwigia decurrens Distinctive Seedbox

Ludwigia decurrens
Distinctive Seedbox

Ludwigia decurrens Winged Stem

Ludwigia decurrens
Winged Stem

The tallest plants here, still only a foot or so off the ground, are the Persicaria hydropiperoides – Swamp Smartweed.   On the terminal racemes, the  buds are relatively sparse and interrupted along the tip of the stem.

Persicaria hydropiperoides Flower

Persicaria hydropiperoides
Flower

The joints of these plants are distinctive.  The cilia (hair-like structures) protrude from the top of the  ocrea (the sheath around the stem) and are about the same length as the ocrea.

Persicaria hydropiperoides Ocrea and Cilia

Persicaria hydropiperoides
Ocrea and Cilia

There are an estimated 230 miles of varying shoreline habitat at Falls Lake!   All of the species mentioned above and in the previous article lie within a 50 ft length of shoreline.  I counted 6 additional species blooming in this same area (for example: Symphyotrichum pilosum – Frost Aster, Persicaria longiseta – Oriental Lady’s Thumb….) and I am sure I missed many as most are so small.

Herb Amyx

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Eryngium prostratum and the November Lake Shore

November at the Falls Lake State Recreation Area has brought crystal clear, sunny days and cold nights, with several hard freezes.    The smaller plants along the lake shore, especially in protected inlets, are in a final blooming period before entering dormancy.  Perhaps the hardiest of this lake shore community is Eryngium prostratum – Creeping Eryngo – which prefers the very edge of the water with all its challenges.  Eryngium prostratum is a member of the carrot family (Apiaceae) and is a perennial.  Colonies can reproduce  vegetatively  by extending creeping horizontal shoots, which then root at the nodes and produce new plants.  Under favorable growth conditions, plants can even form tangled mats that cover parts of the shoreline.  But the large jumps in population seem to come from the germination of profuse numbers of seeds.

After a recent dry spell, the water level of Falls Lake has dropped, exposing large bands of sand and mud flats.  Huge numbers of seedling E. prostratum can be seen dotting the mud and sand, looking a lot like stranded Duckweed from a distance.

Eryngium prostratum seedlings

Eryngium prostratum seedlings

The seedlings and the initial leaves are very small.

Eryngium prostratum seedlings

Eryngium prostratum seedlings

Small colonies that germinated at different times often mix together.

Eryngium prostratum

Eryngium prostratum

As the plants grow, symmetrical basal rosettes are formed.

Eryngium prostratum Basal Rosettes

Eryngium prostratum
Basal Rosettes

As new leaves are added, leaf shape begins to change and elongate, and notches appear.  A few plants begin to show fall purple colors.

Eryngium prostratum Older Basal Rosettes

Eryngium prostratum Older Basal Rosettes

Mature plants can still be found in full bloom.  The flowers are either blue or white.

Eryngium prostratum Flowers

Eryngium prostratum Flowers

Last November, one year ago, this area was vastly different.  The lake level had been lower during the summer and heavy fall rains brought the water level up, submerging large numbers of E. prostratum that had formed along the shore.  The plants persisted for many weeks under water but eventually the sustained higher level of the lake caused the loss of most of the plants in the deeper water.  The blanket of tiny seedlings pictured earlier now covers this formerly submerged area.

Eryngium prostratum Submerged Colonies

Eryngium prostratum
Submerged Colonies

The colonies of E. prostratum at Soapstone Cove, below Rockcliff Farm, have diminished greatly over the past several years due to severe bank erosion.  The remaining plants can sometimes be found hanging down the vertical, eroded bank, suspended by their shoots like cliff climbers by their safety ropes.   The eroded banks seem to be one hurdle that the diminutive plants can not easily overcome.

Eryngium prostratum Hanging Down a Vertical Bank

Eryngium prostratum Hanging Down a Vertical Bank

Herb Amyx

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Quercus acutissima – Brief Fall Update

In the Falls Lake game lands, the Sawtooth Oaks (Quercus acutissima) have dropped large numbers of their acorns by late October.  A ten minute search through grass and leaf litter finds only 3 seeds; all the rest of the hundreds of acorns on the ground are empty caps, a tribute to the efficiency (and numbers) of the Whitetail Deer and other game that feast here.

But only several miles from Falls Lake, in the surrounding suburban parking lots, the oak version of carpet-bombing leaves acorns everywhere.

Quercus acutissima Tires Crunch Through Hundreds of Acorns

Quercus acutissima
Tires Crunch Through Hundreds of Acorns

In a classic imbalance of supply and demand, acorns pile up, covering the mulch on landscaped islands in the parking lots.

Quercus acutissima Acorns Cover the Mulch on the Landscape Islands

Quercus acutissima
Acorns Cover the Mulch on the Landscape Islands

Grass struggles to survive through the press of acorns.

Quercus acutissima Piles of Acorns Blot Out the Grass

Quercus acutissima
Piles of Acorns Blot Out the Grass

Most of the seeds are still present in or near the caps. The few birds and squirrels that feed on the acorns can’t make a dent in the huge numbers.

Quercus acutissima Acorns With Uneaten Seeds

Quercus acutissima
Acorns With Uneaten Seeds

These are the unintended consequences of using such a productive species of oak for urban landscaping.

Herb Amyx

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Selaginella (Rock Spikemoss) at Zeagle’s Rock

Colonies of Rock Spikemoss – Selaginella rupestris – have lived on the top of Zeagle’s Rock for many years.  Over the past decade of consistent drought, the colonies have declined in abundance and vigor.  However, with the return of frequent rains this spring and summer, the colonies are recovering and spreading.

Colony of Selaginella rupestris on a lower ledge of Zeagle’s Rock

Colony of Selaginella rupestris on a lower ledge of Zeagle’s Rock

Selaginella rupestris has the widest range of the Spikemosses, with scattered occurrences in the Piedmont and Mountains of North Carolina.  It grows primarily on exposed rock and granite outcrops, but can also be found on sandy soil or gravel.  Rock Spikemoss can become  desiccated in severe drought and recover completely when rains return.   Although often mistaken for moss and overlooked, it is a true vascular plant, related to ferns and clubmosses.

Selaginella rupestris on the left near colonies of mosses and lichens on the right

Selaginella rupestris on the left near colonies of mosses and lichens on the right

Selaginellas are creeping plants with ascendant stems.  In the following two photos, note the branching stems and scale-like leaves.

Closer View of Selaginella rupestris

Closer View of Selaginella rupestris

Selaginella rupestris - Branching Stems and Scale-like Leaves

Selaginella rupestris – Branching Stems and Scale-like Leaves

Other colonies of Selaginella rupestris, in much larger numbers, can be found on the granitic flatrocks of the Mitchell Mill State Natural Area about 20 miles east of Rockcliff Farm.

Herb Amyx

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Polygala incarnata – Procession Flower

Milkworts (family Polygalaceae) are seen most frequently in the Coastal Plain of North Carolina, although a few species are also found in the Piedmont.   Polygala incarnata, Procession Flower, is probably the most common and widespread of the Piedmont natives.  Also known as the Pink Milkwort or the Slender Milkwort, Polygala incarnata has a beautiful but small pink flower, with an elongated tube that is usually more than twice as long as the terminal petal wings.

Polygala incarnata Procession Flower

Polygala incarnata
Procession Flower

Polygala incarnata Procession Flower

Polygala incarnata
Procession Flower

Although Polygala incarnata is considered common, it can be difficult to spot in the field. It blooms in July and August when the other plants of open fields and power lines have grown tall and can hide the blooming stems.   The flowers are only about ½ in. long and cluster in small numbers.   The leaves are thin and linear, and lie along the stem, giving the impression that the plant has no leaves at all (hence the name Slender Milkwort).   The leaves are barely visible in the following photo.

Polygala incarnata Procession Flower

Polygala incarnata
Procession Flower

The common name Procession Flower is based on its historic use in garlands carried in religious processions celebrating the Fifth Sunday After Easter (Wildflowers of the Carolinas – Bowers, Bowers, and Tekiela).   Procession Flowers must have occurred in large colonies, or perhaps still do in some areas, to supply enough plants for garlands.

Herb Amyx

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