White Snakeroot, and a Bit of a Paradox

White Snakeroot (Ageratina altissima) provides food for late summer and fall visitors, primarily small critters.  Its button-like clusters of tiny tubular flowers offer nectar to a variety of potential pollinators, and flower buds and leaves provide food for other insect diners.

White Snakeroot (Ageratina altissima)

In my shade garden in central New Jersey, Bumble Bees and Small Carpenter Bees (Ceratina species) drink happily from the flowers.

White Snakeroot (Ageratina altissima) with Small Carpenter Bee (Ceratina species)

On a late September Sunday at Garden in the Woods in Framingham, Massachusetts, I watched while Bumble Bees and Honey Bees took advantage of White Snakeroot’s abundant nectar.

White Snakeroot (Ageratina altissima) with Bumble Bee (Bombus species)

White Snakeroot (Ageratina altissima) with Honey Bee (Apis mellifera)

In a sunny woods-edge location at Bowman’s Hill Wildflower Preserve near New Hope, Pennsylvania, several butterfly species found needed nourishment in the nectar  White Snakeroot flowers offered.

Painted Ladies and Sachem helped themselves to White Snakeroot’s sustaining beverage. These butterflies have been around much of the summer and fall, drinking from the flowers in bloom, moving from one species to the next as the season changed.

Painted Lady butterfly drinking nectar from White Snakeroot (Ageratina altissima)

Sachem drinking nectar from White Snakeroot (Ageratina altissima)

I was excited to see a Fiery Skipper, a butterfly that is rare in Pennsylvania, but a common resident in the southern United States. Fiery Skippers are among the butterfly species that regularly attempt to push the envelope of their range by emigrating to the north. White Snakeroot’s refreshing nectar rewarded this individual for its exploration efforts.

Fiery Skipper drinking nectar from White Snakeroot (Ageratina altissima)

Meanwhile, a Monarch fueled up for a flight in the opposite direction, heading south towards its winter territory in Mexico.

Monarch drinking nectar from White Snakeroot (Ageratina altissima)

If these potential pollinators do the job for which White Snakeroot has enticed them to visit its flowers, pollination occurs, and a type of fruit, called an achene, develops. The achene looks like a seed with a tiny hair-like parasol attached, designed to be dispersed by the wind to a favorable place for another White Snakeroot plant to germinate and grow.

White Snakeroot (Ageratina altissima), ready to disperse its fruit

At Bowman’s Hill Wildflower Preserve, an insect that looked a bit like a stink bug turned out to be the opposite – Harmostes fraterulus, one of the scentless plant bugs. Pennsylvania is thought to be the northern edge of Harmostes fraterulus’s range. Scentless plant bugs are a group of true bugs that lack glands to produce an unpleasant smell, quite unlike stink bugs who are named for their ability to do this. Harmostes fraterulus feeds on the flowers of several Aster (Asteraceae) family members, of which White Snakeroot is one.

Harmostes fraterulus on White Snakeroot (Ageratina altissima)

It’s interesting that this small insect is able to eat parts of White Snakeroot, since this plant contains potent toxins evolved to prevent herbivores from consuming it. These toxins are so effective that they can be fatal to mammals.  As you might guess, deer do not eat this plant.  If cows graze on a sufficient amount of White Snakeroot, the milk they produce is toxic to humans.  In the nineteenth century, many people became sick or even died as a result of drinking this tainted milk, most famously, Abraham Lincoln’s mother.

While this plant’s chemical defenses are potent enough to sicken or even kill large mammals, some tiny insects have successfully adapted to use this plant as their food source (host plant). A type of small fly species, a midge named Schizomyia eupatoriflorae, specializes on White Snakeroot buds.  The larvae of this midge live inside the plant tissue, prompting the plant to produce a rounded gall that the developing midge uses for both food and shelter until it is ready to emerge as an adult.

White Snakeroot (Ageratina altissima) with galls caused by the plant’s reaction to being used by a midge, Schizomyia eupatoriflorae

Flowers often have a lower concentration of a plant’s chemical defenses than do the other plant parts such as leaves and stems. But there are even insects who have evolved to specialize on White Snakeroot’s leaves.  The one of which I most often see evidence is a leaf miner, Liriomyza eupatoriella, a type of fly. The larvae of Liriomyza eupatoriella develop between the outer layers of the leaf, feeding on the tissues inside.

White Snakeroot (Ageratina altissima) with leaf mines caused by a leaf mining fly, Liriomyza eupatoriella

Mammals have plenty of other food alternatives (at least for now) without having to evolve a tolerance for White Snakeroot’s toxins. But tiny insects may gain an advantage if they can specialize on food that few others can consume (and live to tell the tale!), especially a relatively common food source like White Snakeroot.

Despite its toxicity, several Native American tribes found medicinal uses for White Snakeroot, often using the root, but other plant parts as well. Some sources say that a poultice to treat snakebites was made from the root, resulting in the common name, White Snakeroot.

White Snakeroot is a plant of woods and woods edges. It prefers light shade but can tolerate partial sun, with moist to slightly dry soils.  In Canada it is native in Ontario and Quebec provinces and the Northwest Territories, and in the United States from Maine to eastern North Dakota, south to Texas and the Florida panhandle, although it is much less widespread in the southeastern U.S.

American Goldfinch, taking refuge on White Snakeroot (Ageratina altissima)

 

Resources

Brock, Jim P.; Kauffman, Ken. Kaufman Field Guide to Butterflies of North America.  2003.

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

Coffey, Timothy. The History and Folklore of North American Wildflowers.  1993.

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

Eiseman, Charley; Charney, Noah. Tracks & Sign of Insects and Other Invertebrates. 2010.

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

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

Illinois Wildflowers

USDA NRCS Plant Database

Harmostes fraterulus:

Maryland Biodiversity Project

Wheeler, A. G. Jr.; Miller, Gary L. Harmostes Fraterculus (HEMIPTERA: RHOPALIDAE): Field History, Laboratory Rearing, and Descriptions of Immature Stages. 1983.

Wheeler, A. G. Jr.  Harmostes reflexulus (Say) (Hemiptera: Rhopalidae): New Western U.S. Host Records, Analysis of Host-Plant Range, and Notes on Seasonality.  2013.

 

 

 

 

Blackberries, Butterflies, Bees and Birds

Common, or Allegheny, Blackberry (Rubus allegheniensis) brambles are blooming in woodlands and meadows throughout the local areas I frequent in central New Jersey and eastern Pennsylvania.  This Rose (Rosaceae) family member can be found from Quebec to Ontario provinces in Canada, south as far as South Carolina and Oklahoma in the United States.  It is also present in California and British Columbia.

Common, or Allegheny, Blackberry (Rubus allegheniensis)

At Bowman’s Hill Wildflower Preserve, near New Hope, Pennsylvania, I found masses of Wild Blackberry blooming in the meadow. Traditionally, the entire meadow is mowed during the winter, but this year a new method of meadow maintenance was introduced, one recommended by the Xerces Society.  Only part of the site was mowed last year, in order to preserve habitat for overwintering insects, birds, and other animals.  This new technique is already paying off, with an impressive display of flowering Blackberry canes, and an equally impressive variety of native pollinators visiting the flowers.

I wasn’t the only one to discover the Blackberries in bloom. From a distance, I could see that at least three Monarch butterflies were already there, flirting and drinking nectar, drawing me in to get a closer look.  They were my first certain Monarch sighting of the season.

Monarch on Common Blackberry (Rubus allegheniensis)

Monarch on Common Blackberry (Rubus allegheniensis)

The Monarchs weren’t alone. Little Wood Satyrs flitted about, occasionally stopping to drink nectar from the flowers.  Little Wood Satyrs are often found where woodlands meet meadow habitat.

Little Wood Satyr on Common Blackberry (Rubus allegheniensis)

Several Red-banded Hairstreaks visited the flowers, along with a few Zabulon Skippers, Eastern Tiger Swallowtails, and Silver-spotted Skippers.

Red-banded Hairstreak hanging out on Common Blackberry (Rubus allegheniensis)

Eastern Tiger Swallowtail drinking nectar from Common Blackberry (Rubus allegheniensis)

Zabulon Skipper drinking nectar from Common Blackberry (Rubus allegheniensis)

Bees and Common Blackberry have a mutually beneficial relationship. Bees are important pollinators for Common Blackberry, and Common Blackberry is an important source of nectar and pollen for the bees.  While I watched, Mining Bees, Bumble Bees, Carpenter Bees and Honey Bees worked the flowers.

Mining Bee (Andrena species) with Common Blackberry (Rubus allegheniensis)

A different Mining Bee (Andrena species) with Common Blackberry (Rubus allegheniensis)

Female Bumble Bee (Bombus species) foraging on Common Blackberry (Rubus allegheniensis). Notice the huge orange load of pollen she has harvested to take back to her nest to feed her larvae.

Eastern Carpenter Bee (Xylocopa virginica) with Common Blackberry (Rubus allegheniensis).

A pair of soldier beetles, Pennsylvania Leatherwings (Chauliognathus pensylvanicus) were mating at the same time the female impressively foraged the flowers for food, a pretty common beetle behavior combination.

A pair of soldier beetles, Pennsylvania Leatherwings (Chauliognathus pensylvanicus) mating, at the same time the female impressively forages Common Blackberry flowers for food.

A Flower or Syrphid Fly (Toxomerus geminatus) ate pollen from the flowers, probably not helping very much to pollinate the Blackberries.  Flies, bees and even beetles all consume some of the pollen.  Only about 2% of pollen is actually used for pollination. The rest serves as an enticement to flower visitors.

A Flower or Syrphid Fly (Toxomerus geminatus) eats pollen from Common Blackberry (Rubus allegheniensis) flowers

A Flesh Fly, and a Robber Fly disguised as a Bumble Bee paused on Blackberry leaves. As a carnivore, the Robber Fly’s mission is to capture and eat other insects.  The disguise may help it elude predators and seem harmless to its intended prey.

A Robber Fly ( Laphria flavicollis) pausing on a Common Blackberry (Rubus allegheniensis) leaf

A Flesh Fly (Sarcophaga species) on Common Blackberry (Rubus allegheniensis)

At a woods edge location nearby in New Jersey, a Bumble Bee and Orange Sulphur enjoyed the nectar the Blackberries offered.

Bumble Bee (Bombus species) on Common Blackberry (Rubus allegheniensis).

Orange Sulphur drinking nectar from Common Blackberry (Rubus allegheniensis).

Common Blackberry has high value for other animals. The insect flower visitors will help to ensure a late summer feast of blackberries for birds, and mammals from mice to fox, and even bear.  They’re very healthy for humans, too!

Ripe fruit of Common Blackberry (Rubus allegheniensis).

Wild Turkey is one of the many animals that benefit from eating Common Blackberry (Rubus allegheniensis) fruit

During the summer, these Common Blackberry brambles offer the perfect nesting habitat for Indigo Buntings. I saw a flash of blue feathers heading for a nearby tree, so they may already be in the process of establishing their nesting territory.

Male Indigo Bunting in Eastern Red Cedar

Multiflora Rose (Rosa multiflora), another Rose family member, is also in bloom.  This species was introduced from Asia for use in hedgerows, especially around farm fields.  As is so often the case, it turned out the introduction was a bad idea.  Multiflora Rose has since become invasive in much of the United States and Canada.  Several states list it as a noxious weed, and some prohibit it.

Plants and even animals that are introduced in a location far from where they evolved often become a problem in their new environment, since the natural predators with which they evolved are not present. In their native locations, these predators help to keep the plant or animal population in balance with other species.  Without these natural checks, the introduced species can crowd out the native plant species on which the animals with which they evolved depend.  We end up losing both plant and animal species as a result.

There is a family resemblance between Common Blackberry and Multiflora Rose, but it’s fairly easy to tell them apart.

Common Blackberry (Rubus allegheniensis) flowers

Common Blackberry flowers are usually white, about 1-1 ½ inches (2.54-3.8 cm) in diameter. The petals have rounded tips.  A large cluster of greenish pistils, the female reproductive flower parts, are visible at the center of the flowers.  These pistils together produce an aggregation of tiny fleshy fruits (called druplets) that are what we know as a blackberry.  The fruits start out green, turning red and eventually black when they’re ripe.  The stamens (male reproductive parts) surround the pistils.  They have white filaments topped with brownish anthers from which pollen is released.

Multiflora Rose (Rosa multiflora) flowers

Multiflora Rose flowers are also usually white, or rarely pinkish. They are just a bit smaller, and the tip of each petal is notched, not rounded.  There is a single greenish pistil at the center of the flower that produces a single round red berry-like fruit called a hip. The pistil is surrounded by stamens with creamy yellow filaments and darker golden anthers.  Multiflora Rose leaves have a distinctive fringe along the sides of the base of the stem.  This is not present in Common Blackberry.

Where I have seen Common Blackberry and Multiflora Rose in close proximity to each other, the pollinators always choose Common Blackberry. It may be a small sampling for a scientific study, but it seems like a pretty telling endorsement to me!

Eastern Tiger Swallowtail drinking nectar from Common Blackberry (Rubus allegheniensis)

Related Posts

Indigo Buntings – Living on the Edge!

For Information on Meadow Maintenance from the Xerces Society

http://www.xerces.org/wp-content/uploads/2014/09/PollinatorsNaturalAreas_June2014_web.pdf

Mader, Eric; Shepherd, Matthew; Vaughan, Mace; Black, Scott Hoffman; LeBuhn, Gretchen. Attracting Native Pollinators: Protecting North America’s Bees and Butterflies. 2011.

The Xerces Society

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.

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

Mader, Eric; Shepherd, Matthew; Vaughan, Mace; Black, Scott Hoffman; LeBuhn, Gretchen. Attracting Native Pollinators: Protecting North America’s Bees and Butterflies. 2011.

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

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

Illinois Wildflowers

USDA NRCS Database

Lady Bird Johnson Wildflower Center

For Information on Mutiflora Rose

USDA NRCS Database

USDA National Invasive Species Information Center

Center for Invasive Species and Ecosystem Health

 

 

 

Bountiful Blue Wood Aster

Blue Wood or Heart-leaved Aster (Symphyotrichum cordifolium) began its seasonal bloom in late September, and amazingly, at the end of November it’s still possible to find some blossoms.

Blue Wood Aster (Symphyotrichum cordifolium) with Sweat Bee (Halictus species)

Blue Wood Aster (Symphyotrichum cordifolium) with Sweat Bee (Halictus species)

Like all Aster (Asteraceae) family members, each flower ‘head’ of Blue Wood Aster consists of many tiny flowers that bloom gradually over a period of several weeks, offering nectar and pollen to a variety of flower visitors.  Each Blue Wood Aster flower head has an outer ring of ice blue petal-like ray flowers designed to advertise this feast. Tiny tubular disk flowers form the center of the display; this is where Blue Wood Aster makes its bountiful food available in hope that while dining, visitors will pick up pollen and transfer it to another plant of the same species, enabling pollination to occur.

Blue Wood Aster’s disk flowers are pale yellow when they’re in bud and when they first open. They turn pink or magenta as they age, and when they have been successfully pollinated.  This color change is a signal to pollinators, directing them to the receptive yellow flowers which are not yet pollinated and that will reward them with nectar, and steering them away from blossoms that are already satisfactorily pollinated and will not produce a nectar reward.  This evolutionary adaptation makes the most efficient use of both the plant’s and the potential pollinator’s efforts.

To share in the bounty offered by Blue Wood Aster, I invite you to a virtual time-lapse visit to our garden in central New Jersey.  You can see the last Blue Wood Aster blossoms for this year, and a selection of the many of the visitors that this lovely plant hosted throughout the season. Notice that the potential pollinators are generally visiting the yellow disk flowers, those that are still open for business, not the pinkish flowers that have shut down their nectar production.

Bumble Bees are the most frequent visitors.

Bumble Bee (Bombus species) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

Bumble Bee (Bombus species) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

An athletic Eastern Carpenter Bee drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium).

An athletic Eastern Carpenter Bee drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium).

But many species of Sweat Bees (Halictid bees), and even Honey Bees dine on Blue Wood Aster nectar and pollen.

Sweat Bee (Halictus species) with Blue Wood Aster (Symphyotrichum cordifolium)

Sweat Bee (Halictus species) with Blue Wood Aster (Symphyotrichum cordifolium)

Sweat Bee (Halictus species) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

Sweat Bee (Halictus species) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

A gang of Sweat Bees (Halictus species) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

A gang of Sweat Bees (Halictus species) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

Sweat Bees (Halictid bees) of two different species visiting Blue Wood Aster (Symphyotrichum cordifolium)

Sweat Bees (Halictid bees) of two different species visiting Blue Wood Aster (Symphyotrichum cordifolium)

A Sweat Bee (Halictid bee) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

A Sweat Bee (Halictid bee) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

A Sweat Bee (Augochlorella species) investigating Blue Wood Aster (Symphyotrichum cordifolium)

A Sweat Bee (Augochlorella species) investigating Blue Wood Aster (Symphyotrichum cordifolium)

A Sweat Bee (Augochlorella species) investigating Blue Wood Aster (Symphyotrichum cordifolium)

A Sweat Bee (Augochlorella species) investigating Blue Wood Aster (Symphyotrichum cordifolium)

A Honey Bee (Apis mellifera) nectaring from Blue Wood Aster (Symphyotrichum cordifolium)

A Honey Bee (Apis mellifera) nectaring from Blue Wood Aster (Symphyotrichum cordifolium)

A Mason Wasp stopped by for nourishment.

A Mason Wasp (Ancistrocerus species) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

A Mason Wasp (Ancistrocerus species) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

Many fly species paused to drink, most disguised as bees or wasps in an attempt to appear threatening to potential predators.

A Syrphid or Flower fly drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

A Syrphid or Flower fly drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

A Syrphid or Flower Fly (Toxomerous geminatus) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

A Syrphid or Flower Fly (Toxomerous geminatus) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

A Syrphid or Flower Fly (Syrphus ribesii) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

A Syrphid or Flower Fly (Syrphus ribesii) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

A Syrphid or Flower Fly (Sericomyia chrysotoxoides) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

A Syrphid or Flower Fly (Sericomyia chrysotoxoides) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

A Syrphid or Flower Fly (Eristalis tenax) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

A Syrphid or Flower Fly (Eristalis tenax) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

Greenbottle Fly (Lucilia sericata) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

Greenbottle Fly (Lucilia sericata) drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium)

Even late season butterflies and moths were able to refuel on Blue Wood Aster nectar.

A Clouded Sulphur butterfly drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium). Notice the heart-shaped leaves that are characteristic of this species.

A Clouded Sulphur butterfly drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium). Notice the heart-shaped leaves that are characteristic of this species.

A Pearl Crescent butterfly drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium). Not only do these butterflies benefit from the nectar, but their caterpillars dine on the foliage of several aster species.

A Pearl Crescent butterfly drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium). Not only do these butterflies benefit from the nectar, but their caterpillars dine on the foliage of several aster species.

A Corn Earworm Moth drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium).

A Corn Earworm Moth drinking nectar from Blue Wood Aster (Symphyotrichum cordifolium).

A Yellow-collared Scape Moth (Cisseps fulvicollis) and Bumble Bee on Blue Wood Aster (Symphyotrichum cordifolium).

A Yellow-collared Scape Moth (Cisseps fulvicollis) and Bumble Bee on Blue Wood Aster (Symphyotrichum cordifolium).

Meanwhile, a Brown-hooded Owlet Moth caterpillar dined on the leaves and spent flowers of Blue Wood Aster.

Brown-hooded Owlet caterpillar eating Blue Wood Aster (Symphyotrichum cordifolium) leaves and flowers.

Brown-hooded Owlet caterpillar eating Blue Wood Aster (Symphyotrichum cordifolium) leaves and flowers.

Blue Wood Aster is native in much of the eastern half of the United States, and in British Columbia, Manitoba, Ontario, Quebec, Prince Edward Island and Nova Scotia in Canada. It can be found in a variety of habitats, including woodlands, meadows and roadsides.  There may still be some blooming near you!

 

Related Posts

Asters Yield a Treasure Trove!

New England Asters – A Hotbed of Activity!

Mysterious Bumble Bee Behavior

Resources

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

Eastman, John. The Book of Forest and Thicket.  1992.

Mader, Eric; Shepherd, Matthew; Vaughan, Mace; Black, Scott Hoffman; LeBuhn, Gretchen. Attracting Native Pollinators: Protecting North America’s Bees and Butterflies. 2011.

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

Wagner, David L.; Caterpillars of Eastern North America, 2005.

Wilson, Joseph S.; Carril, Olivia Messinger. The Bees in Your Backyard. 2016.

USDA NRCS Plant Database

 

Sneezeweed

Sneezeweed (Helenium autumnale) blooms for many weeks, starting in late summer and continuing through mid-fall, offering nectar and pollen for hungry insect foragers late in the growing season.

Sachem on Sneezeweed (Helenium autumnale)

Sachem on Sneezeweed (Helenium autumnale)

It is a member of the Aster family, a vast group second only to the Orchid family in the number of species it includes. There are Aster family members blooming in early spring, but mid-summer through the end of fall is the time that ‘asters’ really dominate the landscape.  Coneflowers, goldenrods, asters, bonesets, tickseeds, beggar-ticks, dandelions and more all belong to this huge plant family.

Goldenrods and New England Asters (Symphyotrichum novae-angliae) are Aster (Asteraceae) family members

Goldenrods and New England Asters (Symphyotrichum novae-angliae) are Aster (Asteraceae) family members

The Aster family is also sometimes called the Composite family, because their many tiny flowers grow in clusters, called heads, that look to us like a single flower. There are two types of flowers possible in an ‘aster’ flower head, ray flowers and disk flowers.  Sneezeweed has both.  Ray flowers look like petals, and disk flowers are tiny tubular flowers clustered in the center of the flower head.  When both ray and disk flowers are present in a flower head, the ray flowers may not produce any nectar or have any reproductive parts.  In this case, the function of the petal-like ray flowers is primarily to add to the floral display and landing platform that will entice pollinators to come to visit.  The disk flowers are where all the action takes place, offering nectar and pollen to potential pollinators.  The photo below shows a butterfly foraging on the disk flowers of a Sneezeweed flower head.

Pearl Crescent drinking nectar from the disk flowers of a Sneezeweed (Helenium autumnale) flower head (inflorescence). The petal-like floral structures are ray flowers.

Pearl Crescent drinking nectar from the disk flowers of a Sneezeweed (Helenium autumnale) flower head (inflorescence). The petal-like floral structures are ray flowers.

Which brings us to the name, Sneezeweed. Is this the plant that has been causing you to sneeze, making your eyes itchy and watery, and your nose runny?  No!  Well, maybe it’s goldenrod?  No again!  We can tell just by looking at these plants that they are unlikely to cause allergies.  How?  Because they have bright, attractive flowers.  Plants that have showy flowers have evolved to use their floral display and food rewards to entice animals to visit.  The animals, usually insects, become unwitting partners with the plants, helping them to achieve their pollination goals.  The flowers’ pollen is heavy and waxy, designed to adhere to a pollinator’s body and highly unlikely to float in the wind.  Plants that are wind pollinated, like Ragweed, have light, fluffy pollen that may find its way up your nose or in your eyes.

The flowers are visited by bees, butterflies, moths and beetles.

Sweat Bee on Sneezeweed (Helenium autumnale)

Sweat Bee on Sneezeweed (Helenium autumnale)

Pearl Crescent on Sneezeweed (Helenium autumnale)

Pearl Crescent on Sneezeweed (Helenium autumnale)

Ailanthus Webworm Moth on Sneezeweed (Helenium autumnale)

Ailanthus Webworm Moth on Sneezeweed (Helenium autumnale)

A soldier beetle, Pennsylvania Leatherwing (Chauliognathus pensylvanicus) on Sneezeweed (Helenium autumnale)

A soldier beetle, Pennsylvania Leatherwing (Chauliognathus pensylvanicus) on Sneezeweed (Helenium autumnale)

Sneezeweed flowers seem to be a popular location for meeting members of the opposite sex, at least if you are an insect.

Pearl Crescents on Sneezeweed (Helenium autumnale)

Pearl Crescents on Sneezeweed (Helenium autumnale)

Two pairs of beetles on Sneezeweed (Helenium autumnale). The dark pair in the upper right of the flower head are a lady beetle species, Microwesia misella.

Two pairs of beetles on Sneezeweed (Helenium autumnale). The dark pair in the upper right of the flower head are a lady beetle species, Microwesia misella.

Then why is this plant called Sneezeweed? Because many Native American tribes used dried flowers or leaves of this plant as snuff to induce sneezing, especially as a treatment for colds.  Gardeners considering using this plant may find its alternative common name, Helen’s Flower, more appealing.  This name is a reflection of Sneezeweed’s genus, Helenium, and a reference to Helen of Troy.

Sneezeweed has chemicals that are toxic to mammals, so it is highly deer resistant. It is native in 47 of the 48 the contiguous United States (New Hampshire is the exception), and much of Canada.  Sneezeweed can be found in sunny locations with moist or wet soil, in marshes, along river or stream banks and in wet meadows.

Sneezeweed – Not the most enticing name for such a beautiful flower!

Sachem on Sneezeweed (Helenium autumnale)

Sachem on Sneezeweed (Helenium autumnale)

Related Posts

Asters Yield a Treasure Trove

New England Asters – A Hotbed of Activity!

Fall Allergies? Don’t Blame Goldenrod!

Feasting on Green-headed Coneflower

Resources

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

Native American Ethnobotany Database

USDA Forest Service Plant of the Week

USDA NRCS Plant Database

 

 

 

 

 

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