Jewelweed Has a Back-up Plan

Jewelweed leaves emerge from the soil in early spring, the plant continuing to grow and mature until it finally begins to bloom in mid-to-late summer, and on through early fall. The name ‘Jewelweed’ has a few explanations, but the one I like best is that it’s a reflection of the fact that the surface of Jewelweed leaves causes water to bead up, glistening like a jewel.

Jewelweed (Impatiens capensis) with Sweat Bee (Halictid species). Notice the jewel-like drops and silvery sheen of water on the leaves.

Jewelweed (Impatiens capensis) with Sweat Bee (Halictid species). Notice the jewel-like drops and silvery sheen of water on the leaves.

There are two Jewelweed species that are common in eastern North America. One has orange flowers with dark reddish-orange spots or lines at the throat.  Some common names for this orange-flowered species are Jewelweed, Spotted Jewelweed, or Spotted Touch-me-not (Impatiens capensis).

Jewelweed or Spotted Touch-me-not (Impatiens capensis)

Jewelweed or Spotted Touch-me-not (Impatiens capensis)

The other species has yellow flowers, sometimes with reddish-brown dots at the throat, and is known as Pale Jewelweed, Yellow Jewelweed or Pale Touch-me-not (Impatiens pallida).

Pale Jewelweed or Pale Touch-me-not (Impatiens pallida)

Pale Jewelweed or Pale Touch-me-not (Impatiens pallida)

These Jewelweed species are annuals, meaning that each plant dies at the end of the growing season. In order for the species to continue to survive, it must produce seeds each year.  Jewelweed has two strategies to make sure that happens.

Jewelweed’s primary strategy for reproduction is to produce showy flowers that will entice animals to visit, and transfer pollen from one plant to another, successfully achieving cross-pollination.

Jewelweed (Impatiens capensis) with Bumble Bee (Bombus species)

Jewelweed (Impatiens capensis) with Bumble Bee (Bombus species)

When Jewelweed flowers open, their male reproductive parts (the stamens), mature first, making pollen available for transfer from the anthers at the stamen tips.

Pale Jewelweed (Impatiens pallida) with mature stamens at the inside top of the entrance of the blossom

Pale Jewelweed (Impatiens pallida) with mature stamens at the inside top of the entrance of the blossom

Later, the stamens wither and are replaced by the female reproductive parts (the pistils), the receptive stigmas at their tips waiting for a flower visitor to brush them with pollen.

Jewelweed (Impatiens pallida) with mature pistil at the inside top of the entrance of the blossom. (Being visited by a mystery critter!)

Jewelweed (Impatiens pallida) with mature pistil at the inside top of the entrance of the blossom. (Being visited by a mystery critter!)

Jewelweed’s showy flowers produce plenty of nectar to lure potential pollinators to visit. The nectar is found in long spurs at the back of the tubular flowers, so a visitor with a long tongue is most likely to have success accessing this treat.  The orange-flowered Jewelweed attracts a broad variety of insect visitors, including several bee species,

Jewelweed (Impatiens capensis) with Bumble Bee (Bombus species)

Jewelweed (Impatiens capensis) with Bumble Bee (Bombus species)

Jewelweed (Impatiens capensis) with Yellow Bumble Bee (Bombus fervidus)

Jewelweed (Impatiens capensis) with Yellow Bumble Bee (Bombus fervidus)

Jewelweed (Impatiens capensis) with Honey Bee

Jewelweed (Impatiens capensis) with Honey Bee

Jewelweed (Impatiens capensis) with Sweat Bee (Agapostemon species)

Jewelweed (Impatiens capensis) with Sweat Bee (Agapostemon species)

Jewelweed (Impatiens capensis) with Sweat Bee (Halictid species)

Jewelweed (Impatiens capensis) with Sweat Bee (Halictid species)

flies,

Jewelweed (Impatiens capensis) with Flower Fly (Copestylum species)

Jewelweed (Impatiens capensis) with Flower Fly (Copestylum species)

Jewelweed (Impatiens capensis) with Flower Fly (Syrphid species)

Jewelweed (Impatiens capensis) with Flower Fly (Syrphid species)

wasps,

Jewelweed (Impatiens capensis) with Yellowjacket

Jewelweed (Impatiens capensis) with Yellowjacket

and even beetles.

Jewelweed (Impatiens capensis) with Northern Corn Rootworm Beetles

Jewelweed (Impatiens capensis) with Northern Corn Rootworm Beetles

Jewelweed (Impatiens capensis) with beetle, probably Spotted Cucumber Beetle

Jewelweed (Impatiens capensis) with beetle, probably Spotted Cucumber Beetle

These beetles are interested in consuming floral tissue, and are probably not very helpful in assisting Jewelweed in attaining its pollination goal.

Given their anatomy and feeding style, Bumble Bees are among the most likely to help successfully pollinate the flowers. They are the most frequent visitors to Pale Jewelweed.

Pale Jewelweed (Impatiens pallida) with Bumble Bee (Bombus species), at Morrisville Riverfront Preserve, Morrisville, PA

Pale Jewelweed (Impatiens pallida) with Bumble Bee (Bombus species), at Morrisville Riverfront Preserve, Morrisville, PA

Pale Jewelweed (Impatiens pallida) with Bumble Bee (Bombus species) with back brushing stamens as it enters the flower, at Morrisville Riverfront Preserve, Morrisville, PA

Pale Jewelweed (Impatiens pallida) with Bumble Bee (Bombus species) with back brushing stamens as it enters the flower, at Morrisville Riverfront Preserve, Morrisville, PA

Even in the insect world there are individuals who like to cut corners and get something for nothing.  There are insects that cheat, chewing through the spur to directly access the nectar. These insects by-pass the flower opening and its reproductive parts, so they’re no help to Jewelweed in its pollination mission.

Ruby-throated Hummingbirds are valuable pollination partners for Jewelweed. As these energetic little birds move from one Jewelweed flower to another, they are likely to pick up pollen on their heads as they brush against the anthers at the inside top of the flower entrance, subsequently depositing the pollen on the stigma of another flower.  In return, Jewelweed provides an important nectar source for them in late summer and early fall.

Male Ruby-throated Hummingbird

Male Ruby-throated Hummingbird

The name ‘Touch-me-not’ reflects the explosive spring-action opening of ripe fruit capsules. The slightest touch will trigger it, projecting the seeds for a distance of several feet.

Ripe Pale Jewelweed fruit capsule

Ripe Pale Jewelweed fruit capsule

The ripe capsule opens at the slightest touch

The ripe capsule opens at the slightest touch

Animal seed eaters include Ruffed Grouse, Bobwhites, mice and shrews.

Jewelweed also has a back-up plan for producing seed, one that doesn’t rely on the assistance of a third party for pollen transportation. In addition to the showy flowers that entice pollinators, Jewelweed produces cleistogamous flowers, a type of flower that doesn’t open and is self-fertilized. When the fruit capsules produced from these flowers open, the seeds fall in the vicinity of the parent plant.  The combination of the two types of flowers may allow Jewelweed to hold its existing territory, and extend it a bit.

Jewelweed contains lawsone, a compound with antihistamine and anti-inflammatory properties. Jewelweed has been used to treat poison ivy exposure, and stings from stinging nettle and insects.

Jewelweed prefers moist soil, and is often found along streams, in wet meadows, roadsides, swamps and open woods.

Jewelweed (Impatiens capensis ) at Wiessner Woods, Stowe, Vermont

Jewelweed (Impatiens capensis ) at Wiessner Woods, Stowe, Vermont

It may establish a large colony, with individual plants often growing to a height of 5 feet (1.5 meters).

Jewelweed (Impatiens capensis ) at Wiessner Woods, Stowe, Vermont

Jewelweed (Impatiens capensis ) at Wiessner Woods, Stowe, Vermont

The orange-flowered Jewelweed’s (Impatiens capensis) range includes the eastern two-thirds of the United States plus Idaho, Oregon and Washington, and all Canadian provinces and territories, except Nunavit.  Pale Jewelweed (Impatiens pallida) is less common, and more of an eastern species.  It can be found from Newfoundland and Labrador, west to Ontario and eastern North Dakota, and as far south as eastern Oklahoma and South Carolina.

 

Resources

Eastman, John. The Book of Swamp and Bog.  1995.

Eaton, Eric R.; Kauffman, Ken. Kaufman Field Guide to Insects of North America.  2007.

Evans, Arthur V. Beetles of Eastern North America.  2014.

Foster, Steven; Duke, James A. A Field Guide to Medicinal Plants and Herbs of Eastern and Central North America.  2000.

Moerman, Daniel E. Native American Ethnobotany.  1998.

Rhoads, Ann Fowler; Block, Timothy A. The Plants of Pennsylvania.  2007

Colla, Sheila; Richardson, Leif; Williams, Paul. Bumble Bees of the Eastern United States. 2011

USDA Forest Service Plant of the Week – Jewelweed

Illinois Wildflowers

USDA NRCS Plant Database Impatiens capensis

USDA NRDS Plant Database Impatiens pallida

 

 

 

Watching Dragonflies: Eastern Pondhawks

Eastern Pondhawks (Erythemis simplicicollis) are dragonflies that perch when they hunt, usually on low foliage or on the ground.

Female Eastern Pondhawk, perching

Female Eastern Pondhawk, perching

Dragonflies are carnivores. They eat other insects ranging in size from tiny mosquitoes to dragonflies their own size, or for some dragonfly species, even larger.  Dragonflies lay their eggs in or near ponds, streams and lakes.  After the eggs hatch, their larvae develop in the water body, where they eat other aquatic insects, including mosquito larvae. They may even eat tadpoles.

Female Eastern Pondhawk, perching

Female Eastern Pondhawk, perching

Dragonflies have exceptional vision, the best of all insect species. Their large eyes are compound, consisting of thousands of simple eyes, and providing them almost a 360-degree field of vision.  This remarkable ability makes it easy for a dragonfly to spot its next meal, an insect on the wing.  When a dragonfly identifies a likely victim,

Female Eastern Pondhawk, "Whoa, I see a moth! Lunch!"

Female Eastern Pondhawk, “Whoa, I see a moth! Lunch!”

it is able to instantaneously calculate the speed and trajectory of its target’s flight, and determine the necessary speed and path for the dragonfly’s own flight, a calculation that will enable the dragonfly to expeditiously intercept its hapless quarry.  The world’s military forces have spent billions trying to replicate this capability!

Female Eastern Pondhawk, with moth. "Delicious!"

Female Eastern Pondhawk, with moth. “Delicious!”

Dragonflies themselves are prey for other animals, including spiders, tiger beetles, frogs, even fish, and birds such as flycatchers. A dragonfly’s broad range of vision can help alert it to the presence of a predator.  Its only blind spots are below its body and directly behind its head.  Hunting from ground level as Eastern Pondhawks do compensates for one of those blind spots.

A perch on a water lily leaf may leave a dragonfly vulnerable to aquatic predators like frogs or fish.

Male Eastern Pondhawk, perching

Male Eastern Pondhawk, perching

But a rock or other ground surface is usually pretty safe from predators from below.

Male Eastern Pondhawk, perching

Male Eastern Pondhawk, perching

Any of these perches offer a suitable takeoff surface for an Eastern Pondhawk to launch into flight and snag its next meal.

Male Eastern Pondhawk with insect. "Yum! This little critter didn't have a chance."

Male Eastern Pondhawk with insect. “Yum! This little critter didn’t have a chance.”

Look for Eastern Pondhawks in the neighborhood of any vegetated wetland.

Resources

Paulson, Dennis. Dragonflies and Damselflies of the East.  2011.

 

 

Swamp Rose Mallow – for Bees, Butterflies, Beetles, Birds and Beauty

Swamp Rose Mallow (Hibiscus moscheutos)

Swamp Rose Mallow (Hibiscus moscheutos)

The huge, showy blossoms of Swamp Rose Mallow (Hibiscus moscheutos), a member of the Mallow (Malvaceae) family, begin to appear in mid-summer, and continue into early fall.  The flowers are most often pink

Swamp Rose Mallow (Hibiscus moscheutos)

Swamp Rose Mallow (Hibiscus moscheutos)

or white, sometimes with a red throat, inspiring a different common name, Crimsoneyed Rose Mallow.

Swamp Rose Mallow (Hibiscus moscheutos)

Swamp Rose Mallow (Hibiscus moscheutos)

But deeper shades of pink and even red are possible.

Swamp Rose Mallow (Hibiscus moscheutos)

Swamp Rose Mallow (Hibiscus moscheutos)

Eastern Tiger Swallowtail butterfly nectaring at Swamp Rose Mallow (Hibiscus moscheutos)

Eastern Tiger Swallowtail butterfly nectaring at Swamp Rose Mallow (Hibiscus moscheutos)

Insects like the Eastern Tiger Swallowtail in the photo above are enticed to visit Swamp Rose Mallow’s flowers for the nectar accessible through slits at the base of the flower.

In addition to seeking nectar, bees visit to harvest the abundant pollen the flowers offer. Bees eat pollen, and female bees gather it to provision their nests with this nutritious food for their larvae.  The Rose Mallow Bee (Ptilothrix bombiformis) is a specialist forager that only eats the pollen of plants in this genus (Hibiscus) and one other, Morning Glories (Ipomoea).

Bees harvesting pollen from Swamp Rose Mallow (Hibiscus moscheutos). Note the pollen grains all over their bodies.

Bees harvesting pollen from Swamp Rose Mallow (Hibiscus moscheutos). Note the pollen grains all over their bodies.

Numerous stamens (the male reproductive parts) form a tube that encircles the pistils (female reproductive parts). Each stamen is topped by an anther that releases pollen.  At the tips of the pistils are the stigmas, the receptive part of the pistil where the pollen must be deposited in order to initiate pollination.  The stigmas extend significantly beyond the stamens, separating them from the flower’s own pollen, thus decreasing the chances that the flower will be self-pollinated.

Bee harvesting pollen from Swamp Rose Mallow (Hibiscus moscheutos). Note the stigmas to the left of the bee.

Bee harvesting pollen from Swamp Rose Mallow (Hibiscus moscheutos). Note the stigmas to the left of the bee.

Bees are thought to be the primary pollinators of Swamp Rose Mallow, in spite of the fact that they devour vast quantities of its pollen.  It also seems plausible that large butterflies such as the Eastern Tiger Swallowtail are effective pollinators of Swamp Rose Mallow. Butterflies visit the flowers purely for nectar; they have no interest in consuming pollen.  Butterflies head for the nectaries, accessed through slits at the throat of the flower.  As the butterflies drink, their bodies brush against the anthers, picking up pollen.  When the butterfly moves on to a different flower, some of that pollen may adhere to the stigmas of the new flower, triggering pollination.

Eastern Tiger Swallowtail nectaring at Swamp Rose Mallow (Hibiscus moscheutos). The butterfly's wings and body brush against the anthers, picking up pollen.

Eastern Tiger Swallowtail nectaring at Swamp Rose Mallow (Hibiscus moscheutos). The butterfly’s wings and body brush against the anthers, picking up pollen.

Eastern Tiger Swallowtail nectaring at Swamp Rose Mallow (Hibiscus moscheutos). The butterfly's wings and body brush against the flower's stigmas, depositing pollen, then against the anthers, picking up pollen.

Eastern Tiger Swallowtail nectaring at Swamp Rose Mallow (Hibiscus moscheutos). The butterfly’s wings and body brush against the flower’s stigmas, depositing pollen, then against the anthers, picking up pollen.

There isn’t much waste in nature.  Bees even scavenge pollen that has fallen onto the flower petals.  Beetles join the bees at this pollen feast.  Hibiscus Seed Beetles (Althaeus hibisci) are primarily interested in eating the seeds of Swamp Rose Mallow and other related species, but while they wait for the seeds to become available, they also consume pollen.  As an additional benefit, cruising the flowers is an effective way for the beetles to hook up with members of the opposite sex!

Bee and Hibiscus Seed Beetles (Althaeus hibisci) scavenging for pollen that has fallen onto the petals of a Swamp Rose Mallow (Hibiscus moscheutos) flower.

Bee and Hibiscus Seed Beetles (Althaeus hibisci) scavenging for pollen that has fallen onto the petals of a Swamp Rose Mallow (Hibiscus moscheutos) flower.

Hibiscus Seed Beetles (Althaeus hibisci)

Hibiscus Seed Beetles (Althaeus hibisci)

Swamp Rose Mallow benefits butterflies in other ways.  It is a potential food plant for the caterpillars of several butterflies, including the Gray Hairstreak, Common Checkered-skipper, and Painted Lady.

Gray Hairstreak on goldenrod. The caterpillars of the Gray Hairstreak butterfly eat the foliage of members of the Mallow (Malvaceae) and Pea (Fabaceae) families, as well as some other plants.

Gray Hairstreak on goldenrod. The caterpillars of the Gray Hairstreak butterfly eat the foliage of members of the Mallow (Malvaceae) and Pea (Fabaceae) families, as well as some other plants.

Common Checkered-skipper on aster. The caterpillars of the Common Checkered-skipper butterfly have evolved to eat plants from the Mallow (Malvaceae) family.

Common Checkered-skipper on aster. The caterpillars of the Common Checkered-skipper butterfly have evolved to eat plants from the Mallow (Malvaceae) family.

Painted Lady on Purple Coneflower (Echinacea purpurea). The Painted Lady is the most widespread butterfly in the world. It is a generalist, with its caterpillars able to eat plants from the Mallow (Malvaceae) and Pea (Fabaceae) families, along with thistles, sunflowers and many other plants.

Painted Lady on Purple Coneflower (Echinacea purpurea). The Painted Lady is the most widespread butterfly in the world. It is a generalist, with its caterpillars able to eat plants from the Mallow (Malvaceae) and Pea (Fabaceae) families, along with thistles, sunflowers and many other plants.

Birds also benefit from the presence of Swamp Rose Mallow. Red-winged Blackbirds may use it as a nesting site.

Male Red-winged Blackbird

Male Red-winged Blackbird

Swamp Rose Mallow’s seeds are a fall and winter source of food for birds,

Swamp Rose Mallow (Hibiscus moscheutos) fruit capsules open to release their seeds.

Swamp Rose Mallow (Hibiscus moscheutos) fruit capsules open to release their seeds.

including Northern Pintails, Wood Ducks and Blue-winged Teal.

Northern Pintails with Swamp Rose Mallow (Hibiscus moscheutos) in winter

Northern Pintails with Swamp Rose Mallow (Hibiscus moscheutos) in winter

Wood Duck pair in non-breeding plumage. (Female left, male right.)

Wood Duck pair in non-breeding plumage. (Female left, male right.)

Blue-winged Teals

Blue-winged Teals

Swamp Rose Mallow is native from Ontario, New York and Massachusetts in the north, south to the southeastern and south central United States. It can grow to a height of about 6.5 feet (2 meters).  Swamp Rose Mallow’s natural habitats are primarily wetlands, include swamps and marshes

Swamp Rose Mallow (Hibiscus moscheutos) at the Abbott Marshlands, Hamilton Township, Mercer County, New Jersey

Swamp Rose Mallow (Hibiscus moscheutos) at the Abbott Marshlands, Hamilton Township, Mercer County, New Jersey

and wet meadows.

Swamp Rose Mallow (Hibiscus moscheutos) in the meadow at Bowman's Hill Wildflower Preserve, New Hope, PA

Swamp Rose Mallow (Hibiscus moscheutos) in the meadow at Bowman’s Hill Wildflower Preserve, New Hope, PA

Resources

Cech, Rick; Tudor, Guy. Butterflies of the East Coast.  2005.

Rhoads, Ann Fowler; Block, Timothy A. The Plants of Pennsylvania.  2007

Willmer, Pat. Pollination and Floral Ecology. 2011

Illinois Wildflowers

Shimamura, Ryouji; Kachi, Naoki; Kudoh, Hiroshi; Whigham, Dennis F. Visitation of a specialist pollen feeder Althaeus hibisci Olivier (Coleoptera: Bruchidae) to flowers of Hibiscus moscheutos L. (Malvaceae). 2004.

USDA NRCS Plant Database

U.S. Forest Service Database

Klips, Robert A.; Sweeney, Patricia M.; Bauman, Elisabeth K. F.; Snow, Allison A. Temporal and Geographic Variation in Predispersal Seed Predation on Hibiscus moscheutos L. (Malvaceae) in Ohio and Maryland, USA. 2005.

 

 

Who Uses Black Cohosh?

Black Cohosh (Actaea racemosa, synonym Cimicifuga racemosa) blooms in mid-summer, lighting up the forest understory.

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa)

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa)

The spikes of white flowers seem to glow even in the dark, begging to be called Fairy Candles, one of the other common names by which Black Cohosh is known.

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa)

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa)

Black Cohosh flowers are arranged in long narrow clusters called racemes, blooming from the bottom of the flower stalk to the top. Each individual flower looks like a pom-pom, formed by an aggregation of many stamens (the male reproductive parts) surrounding a single pistil (the female reproductive part).

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa) flowers

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa) flowers

Black Cohosh depends on the assistance of animals to achieve pollination. The flowers are visited by many species of insects whose bodies may come in contact with pollen dispensed from anthers at the tips of the stamens.  Some of that pollen may adhere to the insect’s body.  When the insect moves to a flower of another Black Cohosh plant and brushes against the flower’s stigma (the receptive part of the pistil), then Black Cohosh’s pollination goal is achieved.

It’s not an accident that insects visit the flowers. Plants and animals have evolved together over centuries to depend on each other.  About 80% of flowering plants depend on animals to carry their pollen to other plants of the same species, helping them achieve successful cross-pollination.  In exchange, many animals depend exclusively, or for at least part of their diet, on plants.

The most common food enticements that plants offer to flower visitors are nectar and pollen. Many insects visit flowers for nectar, but some are also interested in eating pollen, and in the case of bees, harvesting it to bring back to their nests to feed their larvae.

Black Cohosh has evolved a strategy of offering pollen, but not nectar, to entice potential pollinators. Plants evolve to be as efficient as possible, trying not to expend unnecessary resources.  Black Cohosh is able to attract enough visitors to its flowers by offering them pollen only.

Insects want to eat pollen and plants want insects to transport their pollen to another plant of the same species. If this sounds like a potential conflict of interest, it is.  Only about 2% of pollen is actually used for pollination.  Potential pollinators or their offspring eat much of the remaining 98%.

In spite of the fact that another common name for Black Cohosh is Bugbane, many insects are more attracted than deterred by its fragrance. Bees, flies and beetles visit Black Cohosh flowers to eat or harvest pollen.  While I watched for just a few minutes, the activity at a small group of Black Cohosh plants included bees, flies and beetles.  Bumble Bees, Sweat Bees, and Leaf-cutter Bees, all worked the flowers.

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa) with Leafcutter bee (Megachile species)

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa) with Leafcutter bee (Megachile species)

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa) with Sweat bee (Haictidae)

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa) with Sweat bee (Haictidae)

Bumble Bee visits were the most brief. They stopped for just a few seconds per plant before moving on to another.  It may seem counterintuitive, but this may make Bumble Bees the most successful of Black Cohosh’s cross-pollinators, since they are the most likely to move the pollen to a different plant.

A Flower or Syrphid Fly (Toxomerus geminatus) dined on the flowers’ pollen.

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa) with Flower Fly (Toxomerus geminatus)

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa) with Flower Fly (Toxomerus geminatus)

At least two species of tiny Tumbling Flower Beetles (Falsomordellistena pubescens and Mordellistena fuscipennis) munched on the flowers’ tissues.    Tumbling Flower Beetles are named for their behavior when threatened; they bounce and tumble unpredictably and may fly away, carrying pollen to another plant, possibly helping to meet Black Cohosh’s pollination needs.

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa) with Tumbling Flower Beetle (Falsomordellistena pubescens) in upper right

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa) with Tumbling Flower Beetle (Falsomordellistena pubescens) in upper right

The Tumbling Flower Beetles were joined by at least three species of Longhorn Beetles, the Banded Longhorn Beetle (Typocerus velutinus), and two others, Metacmaeops vittata, and Analeptura lineola.

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa) with Longhorn Beetle (Metacmaeops vittata), upper right, and Tumbling Flower Beetles (Mordellistena fuscipennis)

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa) with Longhorn Beetle (Metacmaeops vittata), upper right, and Tumbling Flower Beetles (Mordellistena fuscipennis)

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa) with Longhorn Beetle (Analeptura lineola), center, and Tumbling Flower Beetle (Mordellistena fuscipennis)

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa) with Longhorn Beetle (Analeptura lineola), center, and Tumbling Flower Beetle (Mordellistena fuscipennis)

For an insect, visiting Black Cohosh flowers is not without its risks. Predators like the perfectly camouflaged Crab Spider in the photo below may be lurking in the shadows, waiting for an unwary victim.

Crab Spider with a fly victim (upper left), bee and Tumbling Flower Beetle on Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa)

Crab Spider with a fly victim (upper left) on Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa) with bee and Tumbling Flower Beetle

Black Cohosh is the only food Appalachian Azure butterfly caterpillars can eat. Female butterflies lay their eggs on flower buds.  When the caterpillars hatch, they begin eating the buds and flowers, moving on to leaves if no flowers remain.  Like the other Azure butterfly caterpillars, the Appalachian Azure caterpillars are protected by ants in exchange for the delicious honeydew the caterpillars excrete.  Depending on the species, ants have different forms of defensive weapons; they may bite, sting, or spray an acid at their enemy targets, deterring even birds from their prey.

Appalachian Azure caterpillar being tended by ants, on Black Cohosh (Actaea racemosa) flower buds

Appalachian Azure caterpillar being tended by ants, on Black Cohosh (Actaea racemosa) flower buds

Although I have seen Appalachian Azure caterpillars, I’ve never seen the butterfly. The Appalachian Azure closely resembles the Summer Azure, pictured below.

Summer Azure

Summer Azure

People use Black Cohosh, primarily the root, for medicinal purposes. Black Cohosh contains chemical compounds that are anti-inflammatory, antirheumatic, and that have efficacy in managing female reproductive system problems.  Black Cohosh is approved in Germany for treating menopausal symptoms.  Several indigenous Native American tribes also used Black Cohosh to treat rheumatism and other ailments.

Black Cohosh is native primarily in the eastern United States and the Canadian provinces of Quebec and Ontario. It grows in rich, moist woods, in ravines and on slopes.  Its height can range from just over two feet (.7 meters) to as much as eight feet (2.5 meters).  Black Cohosh will light up a shade garden, blooming from late June through early August.

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa)

Black Cohosh (Actaea racemosa, syn. Cimicifuga racemosa)

Who uses Black Cohosh? Insects do, including bees, flies, beetles, ants, and butterflies; spiders and other predators of the insects feeding there do, and even people use it, for medicinal purposes and for the beauty it brings to a garden.

Related Posts

Spring Azures

Resources

Cech, Rick; Tudor, Guy. Butterflies of the East Coast.  2005.

Eaton, Eric R.; Kauffman, Ken. Kaufman Field Guide to Insects of North America.  2007.

Eisner, Thomas. For Love of Insects.  2003.

Evans, Arthur V. Beetles of Eastern North America.  2014.

Foster, Steven; Duke, James A. A Field Guide to Medicinal Plants and Herbs of Eastern and Central North America.  2000.

Hoffmann, David. Medical Herbalism.  2003.

Marshall, Stephen A. Insects Their Natural History and Diversity. 2006.

Rhoads, Ann Fowler; Block, Timothy A. The Plants of Pennsylvania.  2007

Willmer, Pat. Pollination and Floral Ecology. 2011

USDA NRCS Plant Database

 

 

White Beardtongue for Pollinators

White or Foxglove Beardtongue (Penstemon digitalis) blooms in late spring to early summer, offering nectar and pollen to flower visitors.  It’s easy to recognize in fields and along roadsides by its upright habit and its inflorescence of many whitish flowers, all positioned perpendicularly to the stem.  The name Penstemon reflects the fact that these flowers each have five male flower parts, called stamens.  ‘Foxglove’ and ‘digitalis’ both refer to the shape of the flowers, which resemble those of Foxglove (Digitalis purpurea).

White or Foxglove Beardtongue (Penstemon digitalis)

White or Foxglove Beardtongue (Penstemon digitalis)

The white flowers beckon to a variety of bees who are enticed by the possibility of a meal of nectar and pollen, with the purple lines (nectar guides) on the throat of the flower showing them the way.

Bufflehead Mason Bee (Osmia bucephala) on White Beardtongue (Penstemon digitalis)

Bufflehead Mason Bee (Osmia bucephala) on White Beardtongue (Penstemon digitalis)

Sweat Bee on White Beardtongue (Penstemon digitalis)

Sweat Bee on White Beardtongue (Penstemon digitalis)

Bee on White Beardtongue (Penstemon digitalis)

Bee on White Beardtongue (Penstemon digitalis)

In addition to feeding themselves, female bees also harvest pollen and nectar to provision their nests for their larvae. But if bees are eating and harvesting the pollen, how will the flowers be pollinated?  Will there be any pollen left to fulfill the plant’s goal of reproduction?

Female Bumble Bee on White Beardtongue (Penstemon digitalis). Note the harvested food on her hind leg.

Female Bumble Bee on White Beardtongue (Penstemon digitalis). Note the harvested food on her hind leg.

Although much of its pollen is used to entice and reward insect visitors, White Beardtongue’s strategy is to deposit pollen on its flower visitors’ bodies in a place that can’t be easily reached for grooming.

The flowers have both male and female parts, but they are sequentially unisexual. The male flower parts, or stamens, mature first, with the anthers at their tips opening up to release pollen. Although White Beardtongue has five stamens, only four are capable of producing fertile pollen. These four stamens are all positioned just below the ‘roof’ of the flower tube, or corolla.  The dark brown anthers, which contain the pollen, are at the tips of the stamens, clustering above the center of the entrance to the flower.

White Beardtongue (Penstemon digitalis) in the male phase. The dark brown anthers are clustered just below the center of the ‘roof’ of the flower.

White Beardtongue (Penstemon digitalis) in the male phase. The dark brown anthers are clustered just below the center of the ‘roof’ of the flower.

When the flowers are in this phase, a visitor like the Bumble Bee in the photo below may enter the flower, and be brushed with pollen on the top of its head, thorax or even its tongue (proboscis).

Bumble Bee on White Beardtongue (Penstemon digitalis).

Bumble Bee on White Beardtongue (Penstemon digitalis).

After a day or so, the anthers begin to wither and the female flower part begins to mature, the sticky stigma at its tip becoming receptive to pollen. The style extends and curves downward, taking the same position that the anthers once held.

White Beardtongue (Penstemon digitalis) in the female phase. The stigma has replaced the anthers just below the center of the ‘roof’ of the flower.

White Beardtongue (Penstemon digitalis) in the female phase. The stigma has replaced the anthers just below the center of the ‘roof’ of the flower.

If a bee carries the pollen to a flower in the female phase, it will generally enter the flower in the same way, depositing the pollen on the receptive stigma. Success!  White Beardtongue’s pollination strategy has worked.

Bumble Bee depositing pollen on stigma of a White Beardtongue (Penstemon digitalis) in the female phase.

Bumble Bee depositing pollen on stigma of a White Beardtongue (Penstemon digitalis) in the female phase.

Some pollen may fall on the ‘floor’ of the flower, where the fifth stamen is positioned. This stamen is sterile; it does not produce its own pollen.  It is somewhat hairy, giving the plant its common name ‘beardtongue’.  This hairy stamen may catch some of the fallen pollen and deposit it on an insect visitor as it brushes past, a secondary means of pollen dispersal.  Some smaller bees may cling upside down while foraging for pollen.

Bee visiting White Beardtongue (Penstemon digitalis), possibly harvesting pollen

Bee visiting White Beardtongue (Penstemon digitalis), possibly harvesting pollen

Butterflies and even hummingbirds may stop by for nectar. They may not be as effective in pollinating White Beardtongue as the bees are if their anatomy and behavior is not as good a match for the anatomy of the flower.  On the plus side, neither butterflies nor hummingbirds harvest pollen, so any that does adhere to them has the possibility of being deposited on another flower.

Hobomok Skipper butterfly visiting White Beardtongue (Penstemon digitalis) for nectar. It may be just the right size to pick up or deliver pollen on its head.

Hobomok Skipper butterfly visiting White Beardtongue (Penstemon digitalis) for nectar. It may be just the right size to pick up or deliver pollen on its head.

White Beardtongue blooms for a period of about a month in June to early July. It is native in the eastern two-thirds of the United States, and is found in several Canadian provinces.  It can tolerate sun to part shade in dry to somewhat moist, well-drained soil, and grows to a height of 2-5 feet (6 – 15 decimeters).  It’s a good addition to a natural area or a pollinator garden.

Bumble Bee visiting White Beardtongue (Penstemon digitalis)

Bumble Bee visiting White Beardtongue (Penstemon digitalis)

Here are some other early summer blooming plants that are important for pollinators:

Milkweed – It’s Not Just for Monarchs

What Good is Dogbane?

Resources

Eastman, John. The Book of Field and Roadside.  2003.

Holm, Heather. Pollinators of Native Plants.  2014.

Willmer, Pat. Pollination and Floral Ecology. 2011

Illinois Wildflowers

Lady Bird Johnson Wildflower Center Plant Database

Ontario Wildflowers

USDA NRCS Plant Database