Crayon-colored Hickories

Mockernut Hickory (Carya tomentosa)

The compound leaves of Hickory (Carya species) trees still clinging to their branches are displaying colors that remind me of crayons:  yellow-green, yellow-orange, lemon-yellow, chestnut, burnt umber.  Together with the reds and browns of Oaks, the tans and peach of American Beech, they are part of the mid-fall forest pallette.   Shagbark (Carya ovata), Mockernut (C. tomentosa) and Bitternut (C. cordiformis) are the Hickories I encounter most often.

Mockernut Hickory (Carya tomentosa).

Mockernut Hickory (Carya tomentosa).

Those Hickory leaves may have supported up to 200 different species of butterflies and moths as food for their caterpillars, all without any negative impact on the appearance of the trees. Some of the species Hickories support are Banded and Hickory Hairstreak butterflies, and many moths, including Hickory Tussock, Yellow-shouldered Slug, and the dramatic Hickory Horned Devil, the largest of our native North American caterpillars.

Banded Hairstreak on Indian Hemp (Apocynum cannabinum). Banded Hairstreak caterpillars eat Hickory leaves, as well as some other woody species.

Banded Hairstreak on Indian Hemp (Apocynum cannabinum). Banded Hairstreak caterpillars eat Hickory leaves, as well as some other woody species.

Hickory Tussock Moth Caterpillar

Hickory Tussock Moth Caterpillar

Yellow-shouldered Slug

Yellow-shouldered Slug

The aptly named, acrobatic Hickory Horned Devil caterpillar.

The aptly named, athletic, Hickory Horned Devil caterpillar.

All of those caterpillars are fair game for birds, looking for food for themselves and their growing offspring. Insects, especially caterpilIars, are an important source of food for birds.  It can take thousands of caterpillars to raise a hungry clutch of baby birds.

Wood Thrush at the nest with babies

Wood Thrush at the nest with babies

Some caterpillars may fall victim to other predators, like spiders, predatory wasps or flies, and assassin bugs.

Brown Assassin Bug (Acholla multispinosa) on Bitternut Hickory bud.

Brown Assassin Bug (Acholla multispinosa) on Bitternut Hickory bud.

Hickory nuts also supply food for animals, including people. The husks have four sections that split open to reveal the hard shell protecting the nut ‘meat’ inside.

Shagbark Hickory (Carya ovata) nuts

Shagbark Hickory (Carya ovata) nuts

Mockernut Hickory (Carya tomentosa) nuts split partially open, like this one.

Mockernut Hickory (Carya tomentosa) nuts split partially open, like this one.

Hickory nut on the right, empty husk pieces on the left

Hickory nut on the right, empty husk pieces on the left

Eastern Chipmunks, Red, Gray, Fox and Flying Squirrels, Raccoons, and rabbits all eat Hickory nuts. Squirrels may bury some of the nuts rather than eating them right away.  This habit helps to disperse the Hickories if the squirrels don’t come back and eat the nuts at a later date.

Eastern Chipmunk (with full cheeks!)

Eastern Chipmunk (with full cheeks!)

Gray Squirrel

Gray Squirrel

Fox may also eat Hickory nuts, or they may eat the smaller animals who eat the nuts.

Red Fox eating Gray Squirrel

Red Fox eating Gray Squirrel

Wild Turkeys, Bobwhites, Red-bellied Woodpeckers, Blue Jays, Rose-breasted Grosbeaks and even Wood Ducks are among the birds that consume the tastier species of Hickory nuts.

Red-bellied Woodpecker

Red-bellied Woodpecker

Male Wood Duck in non-breeding plumage

Male Wood Duck in non-breeding plumage

Hickory trees provide food and building material for humans, too.   Shagbark is the species whose nuts are most often sold commercially.  As you might guess from its name, Bitternut Hickory is not sought after for its nuts.  Pecans (Carya illinoinensis) are in this same genus and are an important commercial crop.  Hickory sap can be used to make syrup or other sweeteners.

Shagbark is also the species whose wood is most often used commercially for making handles, ladder rungs, wheel spokes, flooring, and a hickory-smoked flavor for cooking. Named for its shaggy strips of bark, Shagbark Hickory stands out from the crowd.

Can you pick the Shagbark Hickory (Carya ovata) out of the crowd?

Can you pick the Shagbark Hickory (Carya ovata) out of the crowd?

The bark offers warm, dry accommodations for insects and others trying survive the winter.

Spider web on Shagbark Hickory (Carya ovata)

Spider web on Shagbark Hickory (Carya ovata)

Eastern Comma butterflies survive the winter as adults, if they can find a warm dry shelter like a space under the loose bark of Shagbark Hickory (Carya ovata).

Eastern Comma butterflies survive the winter as adults, if they can find a warm dry shelter like a space under the loose bark of Shagbark Hickory (Carya ovata).

Mockernut Hickory also has distinctive bark, but in a completely different way. Its gray, smooth-looking, corky exterior forms sinuous ridges along the length of the trunk.

Mockernut Hickory (Carya tomentosa). Notice the curved ridges in the bark, especially in places where branches have fallen off.

Look for Hickory trees even after their leaves fall. You may be able to identify them by their bark and their buds.  Hickories typically have a single large end bud at the tip of their branches that is usually quite distinctive, different for each species.  There are smaller buds spaced alternately along the length of the branches.

Mockernut Hickory buds are somewhat rounded, echoing the curved pattern of the bark ridges.

Mockernut Hickory (Carya tomentosa) branch in winter. Notice the large end bud with rounded sides.

Mockernut Hickory (Carya tomentosa) branch in winter. Notice the large end bud with rounded sides.

Shagbark Hickory usually retains contrasting bud scales, which you might think of as being reminiscent of the shaggy bark.

Shagbark Hickory (Carya ovata) bud. Notice the bod scales hugging the sides.

Shagbark Hickory (Carya ovata) bud. Notice the scales hugging the sides of the bud.

Bitternut Hickory buds are a bright mustard color that is difficult to mistake for anything else.

Bitternut Hickory (Carya cordiformis), showing its distinctive mustard-colored buds.

Bitternut Hickory (Carya cordiformis), showing its distinctive mustard-colored buds.

As winter turns to spring, watch for these buds to swell and unfold like flowers.

Mockernut Hickory (Carya tomentosa) leaves unfolding in spring.

Mockernut Hickory (Carya tomentosa) leaves unfolding in spring.

Shagbark Hickory (Carya ovata) in spring

Shagbark Hickory (Carya ovata) in spring

The range for Shagbark and Bitternut Hickory includes much of the eastern two-thirds of the United States, and Ontario and Quebec provinces in Canada. Mockernut’s range is similar, but it does not include the Canadian provinces, or some of the northern tier of the United States.

Enjoy the colorful foliage while it lasts!

Mockernut Hickory (Carya tomentosa)

Mockernut Hickory (Carya tomentosa)

Related Posts

Nutritious Fall Foliage: What Makes Leaves So Colorful

American Beech

In Praise of Black Walnut Trees

Resources

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

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

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

Martin, Alexander C.; Zim, Herbert S.; Nelson, Arnold L. American Wildlife & Plants A Guide to Wildlife Food Habits.  1951.

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

Stearn, William T. Stearn’s Dictionary of Plant Names.  1996

Tallamy, Douglas W. Bringing Nature Home.  2007

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

Illinois Wildflowers
http://www.illinoiswildflowers.info/trees/plants/btnt_hickory.html
http://www.illinoiswildflowers.info/trees/plants/mock_hickory.html

Tallamy, Douglas W. Bringing Nature Home

USDA NRCS Plant Database
https://plants.usda.gov/core/profile?symbol=CAOV2
https://plants.usda.gov/core/profile?symbol=caco15
https://plants.usda.gov/core/profile?symbol=CAAL27

The Wood Database

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.

 

 

 

 

Partridge Pea Puzzles

Bright yellow Partridge Pea (Chamaecrista fasciculata) flowers peek out from between the stems of taller grasses and flowering forbs in meadows, prairies, stream banks and other open areas from July through early September.

Partridge Pea (Chamaecrista fasciculata)

Partridge Pea’s flowers are tucked in the leaf axils down the length of the stem.

Partridge Pea (Chamaecrista fasciculata)

Each flower has five yellow petals, with one much longer than the other four, and another partially curled toward the center of the flower, where its reproductive parts are located. A 1992 study showed that the curved petal directs floral visitors to the flower’s reproductive parts, first to the pistil (female reproductive part), and then the stamens (male reproductive parts).[1]  The red smudges on the petals are part of the visual allure to pollinators.

Partridge Pea (Chamaecrista fasciculata)

In the Partridge Pea flower in the photo above you can see the three evenly sized petals at the top, one petal in the lower left that curls toward the center of the flower, and an over-sized petal at the lower right. The stamens are mostly clustered at the middle of the flower.  The pistil resembles a hook projecting from beneath the right-most stamen. It is visible at the top of the over-sized petal.  Imagine a pollinator coming in for a landing using the over-sized petal as a runway, guided by the curved petal, with the red smudges on the petals as beacons. The pollinator brushes first against the receptive stigma at the tip of the pistil, depositing pollen from the last flower visited, then moves on to harvest pollen from the stamens.

Bumble Bee harvesting pollen from Partridge Pea (Chamaecrista fasciculata) flower. Bumble Bees are adept at buzz pollination.

Partridge Pea flowers offer pollen as a reward to their visitors, but they don’t produce nectar. As a result, bees that collect pollen are the most likely visitors of the flowers.  But the bees have to have skills in order to harvest Partridge Pea’s pollen, since it requires special handling in order to access it.  The pollen is dispersed through a slit at the tip of the stamen’s anther.  Pollen can be shaken out of the anther as a result of buzz pollination, a technique in which a bee clings to the flower while vibrating its wing muscles without actually moving its wings.  ‘Milking’ the anther with a series of strokes is another method of successfully harvesting Partridge Pea’s pollen.[2]

Honey Bee harvesting pollen from Partridge Pea (Chamaecrista fasciculata) flower. Honey Bees can’t perform buzz pollination, so may be using the ‘milking’ technique.

Eastern Carpenter Bee harvesting pollen from Partridge Pea (Chamaecrista fasciculata) flower.

Butterflies aren’t interested in Partridge Pea flowers, since they don’t offer nectar. But several butterfly species use Partridge Pea as a food plant for their caterpillars, including the Sleepy Orange and Cloudless Sulphur.

Sleepy Orange drinking nectar from Winged Loosestrife (Lythrum alatum)

Cloudless Sulphur

Gray Hairstreak and caterpillar on Partridge Pea (Chamaecrista fasciculata). Can you see the tiny caterpillar clinging to a leaf in the lower left of the photo?

When I saw a Gray Hairstreak butterfly spending time walking around a Partridge Pea plant, it seemed possible that this was a female laying eggs. Gray Hairstreaks use some Pea family members as caterpillar food, including clovers and tick-trefoils, although I haven’t seen any confirmation that they would use Partridge Pea.

Gray Hairstreak on Partridge Pea (Chamaecrista fasciculata).

A closer look showed that the butterfly was visiting Partridge Pea for nectar after all, but it was nectar that is made available through extrafloral nectaries on the base of the stem of each leaf.  This was a great benefit for the butterfly, but not much help for the plant, since the butterfly offered no services in return.

Gray Hairstreak drinking nectar from an extrafloral nectary on Partridge Pea (Chamaecrista fasciculata)

When present, extrafloral nectaries are generally a plant’s adaptation to entice insects that are predators of herbivores to visit and protect the plant. Ants are especially important in this role, since caterpillars are a very desirable food for them.  Some wasps and lady beetles are also potential protectors of plants.  While they are interested in nectar for themselves, they are also on the hunt for insects to feed to their larvae.  The wasps and lady beetles may rid the plant of the caterpillars or other insects who would eat it.  Nectar is provided in exchange for this protection.

Partridge Pea’s extrafloral nectaries look like tiny open pots, glistening with nectar, an open invitation to thirsty insects cruising through, not all of whom will offer services to the plant.

The two round pot-like appendages near the base of the Partridge Pea (Chamaecrista fasciculata) leaf stems are the extrafloral nectaries. Notice the glistening drops of nectar oozing from them.

While I have seen ants working Partridge Pea extrafloral nectaries, I was surprised at the variety of insects I saw drinking from them at one location I visited. It makes me wonder whether the cost of providing this nectar is worth the protection gained from them.  In addition to the Gray Hairstreak, I watched while a Bumble Bee spent more time visiting the extrafloral nectaries than the flowers.

Bumble Bee drinking nectar from a Partridge Pea (Chamaecrista fasciculata) extrafloral nectary.

After visiting several extrafloral nectaries, the Bumble Bee moved on to a flower.

I saw several Paper Wasps visit the nectaries. Since these wasps hunt caterpillars to feed their larvae, they do have the potential to provide a service in exchange for a tasty drink.

Paper Wasp (Polistes species) drinking from an extrafloral nectary on Partridge Pea (Chamaecrista fasciculata)

Paper Wasp (Polistes species) drinking from an extrafloral nectary on Partridge Pea (Chamaecrista fasciculata)

‘That was tasty!’ Paper Wasp (Polistes species) on Partridge Pea (Chamaecrista fasciculata)

Some accounts of Partridge Pea say that the leaves will sometimes fold up when they are touched. I’ve tried it several times, but I have never had Partridge Pea respond to my touch.  However, I have seen Partridge Pea plants with their leaves folded, so I’m guessing the plant folds its leaves in response to some stimuli, but I haven’t found an explanation for what it might be.  Maybe it’s a mechanism to prevent excessive water loss on hot, dry, or windy days.  Or maybe the plant responds to the touch of a butterfly laying eggs, and wants to minimize the leaf surface available to her.  I wish I knew!

Partridge Pea (Chamaecrista fasciculata) with leaflets folded. What prompted this?

If the name didn’t give away its family heritage, the fruits identify Partridge Pea as a member of the Pea or Bean (Fabaceae) family.  These fruits are an important winter source of food for birds, especially Bobwhites and Greater Prairie Chicken.

Partridge Pea (Chamaecrista fasciculata) with fruits typical of the Pea (Fabaceae) family.

Partridge Pea is an annual, but reseeds itself readily.  It likes sun, and can tolerate poor, dry soils.  It helps to fertilize soils through its release of nitrogen, and is sometimes used in stream bank stabilization.  Partridge Pea is native from Rhode Island to Minnesota in the north, south as far as southeastern New Mexico, and from Texas to Florida.

Partridge Pea (Chamaecrista fasciculate)

Related Posts

Will Work for Food – Extrafloral Nectaries

Cloudless Sulphurs Are on the Move

Sleepy Orange Butterflies are Back

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.

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

Illinois Wildflowers

USDA NRCS Plant Database

USDA NRCS Plant Guide – Partridge Pea

[1], [2] Pollination and the Function of Floral Parts in Chamaecrista fasiculata, Andrea D. Wolfe and James R. Estes, 1992.

Natural Selection on Extrafloral Nectar Production in Chamaecrista Fasciculata: The Costs and Benefits of a Mutualism Trait

 

A Small Beauty: Purple Milkwort

As we walked the path between the woods and the meadow at the Pole Farm section of Mercer Meadows, Wood Nymphs flitted in and out of the foliage, Monarchs flew by, some mating, and a Clouded Sulphur dipped into the path to lay eggs, the tip of her abdomen touching the leaves of White Clover for a split second each.

Monarch butterflies mating

Wood Nymph

Glancing down, I saw a small group of plants that at first glance looked like a type of clover.

Purple Milkwort (Polygala sanguinea).

But it wasn’t clover. The plants had narrow, alternate leaves, and the tiny flowers were tightly packed into a somewhat flat-topped cylindrical cluster.  It was Purple Milkwort (Polygala sanguinea).

In profile, the outside of the flowers in the cluster (inflorescence) look like overlapping scales, similar to those on a pine cone. These scale-like structures are sepals, the outermost appendage of a flower.  When present, sepals protect the other flower parts as they mature.  In Purple Milkwort, two sepals fuse to form these scale-like outer flower parts, each for a separate flower.

Purple Milkwort (Polygala sanguinea), with unknown insect, probably a beetle, investigating its flowers

Viewed from the top, the inflorescence looks like a single very showy flower.

Purple Milkwort (Polygala sanguinea)

A closer inspection tells a different story. The outermost layers of the display look like white petals dipped in purple, but they are the sepals visible when the flower cluster is viewed in profile.  Moving inward, there are tube-like structures, in luscious shades of yellow, peach and a deep bright pink, reminiscent of popsicle colors.  These tubes are the fused petals of the individual flowers that form this cohesive cluster. At the very center of the inflorescence is a bouquet of buds that have not yet opened.  Together these flowers and buds offer an impressive show.

Purple Milkwort (Polygala sanguinea). The fused petals form a tube, initially yellow, then fading to peach and deep pink.

What explains the different colors of the floral tubes? If you look carefully, the yellow flowers are closest to the center of the display.  They are the most recently in bloom, open for business, the bright yellow actively beckoning pollinators.  The peach flowers have been open longer, and are shutting down.  The deep pink flowers have been in bloom the longest, and are no longer seeking pollinators for themselves.   This kind of color change is usually a plant adaptation to direct pollinators only to the receptive flowers that have not yet been pollinated.  It makes the most efficient use of the pollinator’s efforts from the perspective of both the pollinator and the plant.  While the peach and pink flowers are not beckoning pollinators for themselves, they continue to add to the attractiveness of the overall floral display.

This brightly colored display works! It attracts small to medium sized bees and bee-flies with tongues long enough to reach down the floral tube for a nectar reward.  The photos below show a Sweat Bee (Halictid bee, Augochlorini tribe) exploring the flowers.

Sweat Bee (Halictid bee, Augochlorini tribe) exploring a Purple Milkwort (Polygala sanguinea) inflorescence

Sweat Bee (Halictid bee, Augochlorini tribe) positioning its proboscis for a drink from a Purple Milkwort (Polygala sanguinea) flower

Mmmm, delicious! Sweat Bee (Halictid bee, Augochlorini tribe) drinking nectar from a Purple Milkwort (Polygala sanguinea) flower

Purple Milkwort can be found in the ground cover layer of meadows, prairies, open fields and woods edges from Nova Scotia west to Ontario in Canada, and in much of the eastern two-thirds of the United States, except Florida. It can grow to a height of four to sixteen inches (1-4 dm).  Both the common and scientific names reflect the color of the flowers and the milky sap the plant contains.  The genus, Polygala, is derived from Greek words that mean ‘many or much’ and ‘milk’, referring to the sap.  The species, sanguinea, is derived from a word that means ‘blood’.  Other common names for Purple Milkwort are Blood or Field Milkwort, reflecting its color or habitat.  Although common, it’s not always easy to spot this little beauty.

Follow the camera lens to the Purple Milkwort in the shadows in the lower left of the photo.

Resources

Mauseth, James D. Botany An Introduction to Plant Biology.  2014.

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

Stearn, William T. Stearn’s Dictionary of Plant Names.  1996

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

Flora of Wisconsin

Illinois Wildflowers

Minnesota Wildflowers

USDA NRCS Plants Database

 

 

Rewards of a Butterfly Count

Common Buckeye

Why participate in a butterfly count? Well for one thing, you’ll be contributing to a citizen science project that gathers data to help assess how well butterfly species are doing over time.  Are numbers for each species in a given area declining, increasing, staying the same?  Are new species appearing in a location, are any disappearing?

Citizen science is my excuse, but it’s not my reason. I do it because it’s fun.

In mid-July, I participated in a count at Silver Lake Nature Center in Bristol, Pennsylvania. There were six of us.  We started looking for butterflies even before we entered the natural areas, searching carefully while walking across a lawn.  We were rewarded with sightings of Sachem, Peck’s Skippers, Eastern-tailed Blues, Common Buckeyes, Wild-Indigo Duskywings and Horace’s Duskywings.

Wild Indigo Duskywing on White Clover

Horace's Duskywing on White Clover

Horace’s Duskywing on White Clover

Eastern-tailed Blue

Are you wondering what attracted butterflies to the lawn, and why we even thought to look for them there?

It’s not every lawn that would be so productive. We were able to find butterflies in this lawn because it isn’t treated with pesticides or herbicides.  Most of the butterflies we saw were basking on blades of grass or drinking nectar from White Clover (Trifolium repens), a Pea (Fabaceae) family member.  If herbicides were used, the clover wouldn’t be there to feed butterflies, bees and other pollinators.  No crab grass would be available for Sachem and some other butterfly species to use as food for their caterpillars.  Pesticides would kill the butterflies directly.  Another bonus from having White Clover in the lawn is that it acts as a natural fertilizer, releasing nitrogen into the soil in a manner and quantity that can be used effectively by the other plants living there. It actually helps the grass to be healthier.  Even better, there is no excess chemical fertilizer to run off into streams, rivers and other waterways.  Years ago, white clover was included in grass seed mixes for this very purpose, until fashions changed, calling for a monoculture lawn with no clover, dandelions or violets.  Maintaining this uniform green carpet requires regular applications of herbicides to kill everything but grass, and synthetic fertilizer, to keep the grass growing.  The result is an expensive and toxic lawn maintenance regimen, devoid of butterflies, but welcoming to Japanese Beetles. As the fashion trend turns back, lawns become a safer, less toxic place to play for pets, children and even adults.

We worked our way across the lawn to the powerline cut through Delhass Woods. A male Widow Skimmer dragonfly stood guard in the grasses as we approached the entrance.

Male Widow Skimmer dragonfly

This is a much ricer habitat for butterflies, a sunny area filled with diverse plants that provide food for butterflies in the form of nectar, and food for their caterpillars in the form of the leaves of plants on which they specialize.  Plants in the Pea family, including Red Clover (Trifolium pretense), Crown Vetch (Securigera varia), and Wild indigo (Baptisia tinctoria), were a big draw for butterflies.

Wild indigo (Baptisia tinctoria)

Not only do the flowers offer nectar, but Wild Indigo Duskywings, Wood Nymphs, Clouded Sulphurs, Orange Sulphurs and other butterflies use these plants as food for their caterpillars.  All of these species were present in good numbers, along with Common Buckeyes, Peck’s Skippers, and Sachem.

Common Buckeye with Crown Vetch

Common Buckeye with Crown Vetch

Sachem on grape leaf

Pecks Skipper on Red Clover

Clouded Sulphur on Crown Vetch

We saw Wood Nymphs and Spicebush Swallowtails, but they didn’t pose for me this year. Last year they were pre-occupied enough with other activities to be more cooperative.

Spicebush Swallowtail drinking nectar from Turks-cap Lily

Wood Nymphs, mating

Surrounded by such a varied and rich habitat, an open area with woods on either side and a pond nearby, we couldn’t help but occasionally be distracted by birds and other critters, and some plants I don’t often see.

Maryland Meadow Beauty (Rhexia mariana)

Golden Hedge Hyssop (Gratiola aurea)

A Halloween Pennant dragonfly monitored our progress as we finished up our search of the powerline cut.

Female Halloween Pennant dragonfly

After a break, we moved on to the woods, marshes, and gardens. Cabbage Whites were everywhere.  Cabbage Whites aren’t native to North America, and can be a problem for farmers.  Their caterpillars feed on some plants in the mustard or cabbage (Brassicaceae) family. If you have ever found a small green caterpillar in your broccoli or kale (I have), it was probably a Cabbage White.  They have done so well in North America that they are often the species with the highest numbers for a count, as they were this day.  They ignored us while they mated in the woods.

Cabbages Whites mating

Eastern Tiger Swallowtails, Silver-spotter Skippers, Red Admirals and Sachem all enjoyed the nectar Buttonbush (Cephalanthus occidentalis) provided in the marshy areas.  Sachem also enjoyed the garden.

Eastern Tiger Swallowtail on Buttonbush (Cephalanthus occidentalis)

Sachem

A week later I did another butterfly count at Bowman’s Hill Wildflower Preserve near New Hope, Pennsylvania. We had our best year since 2013, seeing twice as many butterflies as we did in 2014-2016.

Eastern Tiger Swallowtail on Joe-pye-weed (Eutrochium purpureum)

Some highlights were Juniper Hairstreaks, a small but beautiful butterfly that is considered ‘locally common’ because it is usually only found near its caterpillar food plant, Eastern Red Cedar (Juniperus virginiana).

Juniper Hairstreak on Short-toothed Mountain Mint (Pycnanthemum muticum)

We saw our highest number of Monarchs in the 6 years we have participated in the count.

Monarch butterfly resting on Yarrow

It was really exciting for me to see so many Sleepy Oranges, a southern species that returned to this Pennsylvania location after a nearly four-year absence.

Sleepy Orange drinking nectar from False Sunflower (Heliopsis helianthoides)

So why do a butterfly count? You’ll get to see beautiful butterflies and other critters interacting with gorgeous plants, and you’ll share the day with people who are enjoying themselves as much as you are, all while contributing to a citizen science effort that monitors the health of butterflies.  And you’ll have fun.

Gray Hairstreak on Grass-leaved Goldenrod (Euthamia graminifolia)

To find a butterfly count near you, check with the North American Butterfly Association.

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