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Photo by Kellen McCluskey

Thursday, August 4

Don't Wait! Ordering Ends Next Week!

NEXT THURSDAY IS THE FINAL DAY to place an order for the Arboretum's Fall Native Plant Sale. Add beauty, diversity, and critical habitat to your gardens with plants from our extensive selection of landscape-ready native trees, shrubs, perennials, ferns, vines, and grasses. 

To provide the healthiest plants possible, we will continue to conduct our sales online with scheduled pickups. This process allows us to efficiently care for the plants and protect them from wind and animals. There will be no shopping at the Arboretum. 

Orders will be accepted through Thursday, August 11 and fulfilled via scheduled, timed pickup slots September 9–10 and 13–17. As always, members receive a discount on plant purchases. Click here to join, renew your membership, or give an Arboretum membership as a gift, or contact Kellen McCluskey at

Click here for more information and to place your order.

For questions regarding plants and/or ordering, please send email to As always, thank you for your support!

Photo by Kellen McCluskey

Join Us for Upcoming Programs

River-Friendly Yards—Friday, August 5, 10–11 a.m.

A river-friendly yard restores the natural environment to benefit water quality, native species, and our local ecosystems. In this ShoreRivers workshop with Darran Tilghman, you'll learn practices, tips, and resources to make positive change in your own backyard. Register here. 

Rapturous Raptors—Saturday, August 20, 10 a.m.–noon

All kids love raptors. Join birder Jim Wilson to learn about the hawks, falcons, and owls found at the Arboretum and on the Eastern Shore—and how they capture prey, care for their young, and more. Click here to register. The class will be offered again on Saturday, August 27

Fireflies! Saturday, August 20, 7:30–9 p.m.

This program is family friendly!

Stay up late for a magical summer evening with the Arboretum's fireflies. Learn firefly facts from naturalist Jenny Houghton, take a guided walk to look for the animals that come out at dusk, and settle in for lemonade and snacks as we watch the show. Click here to register.

Birding for Beginners—Wednesdays beginning August 31, 10–11:30 a.m.

Want to learn more about the birds you see every day? Focusing on size, shape, behavior, and song, birder Jim Wilson will provide the basics of identifying the birds you see at the Arboretum and around your house. You'll also learn about migration, breeding, feather molt, and other topics in this six-week series. Register here or contact Jim with questions at

Goldfinch. Photo by Kellen McCluskey.

Nature Notes

The moth that lay in my path was a knockout. Her white wings were liberally dotted in solid and hollow black spots, and she could easily fill the palm of my hand. Impossible to miss on a background of green grass, she did not appear intent on camouflage. I kneeled and reached out. The moth lay still, lifeless. But was she?


Hypercompe scribonia, also known as the giant leopard moth, is widespread in many parts of North and South America. Its common name is apt, as its wingspan averages three inches. Adults are nocturnal and fly only when night falls. Males are attracted to light more so than females and can sometimes be found clustering around lamps. Males are also larger than females, with a wing length of 2 inches compared to the females' 1.2 inches. 

Adult giant leopard moth. Photo courtesy of Jay Sturner/Wikimedia Commons.

The mating habits of giant leopard moths are worthy of reflection. Mating sessions can take more than 24 hours, during which time the male will occasionally relocate (while still coupled) to thermoregulate. Once the female lays her clutch of approximately 50 pearly eggs, she will die…and the male will immediately look for a new mate.


The offspring of giant leopard moths—giant woolly bear caterpillars—are a harbinger of fall along country roads. Woolly bears cross the road in search of overwintering sites. After hibernation, they’ll emerge in spring to complete their development. Fully grown woolly bears are black and covered in bristly hairs, or setae. If you look closely, you’ll notice small red pores dotting their bodies. These aid in oxygen exchange and are called spiracles.

Woolly bear caterpillar of giant leopard moth. Photo courtesy of Judy Gallagher/Wikimedia Commons.

Giant leopard moths have several defense mechanisms in addition to their bristles. The caterpillars curl into tight balls when threatened. Adults release an acrid yellow fluid and feign death. In their larval form, they feed on a variety of broad-leaved plants. This may ensure that sufficient toxins are ingested to provide a chemical defense. The moths emit clicks to advertise their unpalatableness and to scramble bat sonar.


By the time I returned to the place where I had first spotted the moth, she was gone. Had she been depleted by egg-laying and vulnerable to predation? Or had she merely been tricking me, waiting for my departure to fly off in search of nectar, rotting fruit, or a mate? Either way, I counted myself lucky to have spied her in the first place. In Native American tradition, moths symbolize rebirth, change, and regeneration. Just the sign I needed before the busy fall months ahead.

Jenny Houghton

Assistant Director

Nature Sketchers

In August, you will find an abundance of flora and fauna at the Arboretum that are inspiring subjects for sketching. Despite the intense heat of July, the midsummer landscape is looking quite fresh as climate change brings us wetter summers. In the Parking Lot Alive! gardens, a lush stand of Joe-pye weed (Eupatorium purpureum) greets us with mounds of dusky pink flowers. The orange blossoms of butterfly weed (Asclepias tuberosa), green to purple berries of American beautyberry bush (Callicarpa americana), and yellows of early goldenrod (Solidago juncea) create a colorful patette. Relax and watch as butterflies gracefully float and flit, tiny native bees busily gather pollen, and band-winged grasshoppers (subfamily Oedipodinae) hop and fly in the gardens.

Under the Visitor's Center bridge, the water in the wetland is dotted with duckweed (genus Lemna). A favorite food of turtles, aquatic waterfowl, and fish, duckweed is the smallest known flowering plant. An individual plant has one flat oval leaf about ¼ inch long, a tiny root about twice that length, and flowers so small they are microscopic and rarely seen, though visited by pollinators. Duckweed can reproduce through pollination, but the plant mostly multiplies by forming chains of new stems from buds and can go from a few small dots of green to an entire dense colony very quickly. Floating on ponds, lakes, and slow-moving water, duckweed can be mistaken for pond scum instead of the amazing colony of tiny plants it is. There is a lot of interest in growing this versatile plant commercially for use as livestock feed, fertilizers, biomedicines, and biofuels.

Also blooming in the wetlands are two exotically beautiful native mallows with showy flowers in shades of pink and white. Though they grow almost side by side in the wetlands and bloom at the same time with similar flowers, they are from two completely different plant families. The swamp rose mallow (Hibiscus moscheutos) has white or pink flowers with magenta-red centers. Its leaves are broad and heart shaped. The seashore mallow (Kosteletzyka virginica) has pink flowers with no red in the center. Its leaves are narrower and sword shaped. Both plants are food sources for bees, butterflies, and hummingbirds.

Swamp rose mallow (Hibiscus moscheutos) and

seashore mallow (Kosteletzkya virginica). Sketch by Diane DuBois Mullaly.

In the woodland, two native orchids are blooming. Let's explore and sketch them! Standing at the back door of the Visitor's Center, face the South Meadow and turn right on the South Meadow Loop. Veer right at the Native Bee House, walk into the woods, cross the bridge over Blockston Branch, and take the Upland Trail straight ahead. The first orchid ID markers you will see on your right are for the cranefly orchid (Tipularia discolor), which blooms in July–August. This orchid is found in leaf litter beneath oak trees where there is humus-rich soil, decomposing wood, and a fungus that helps it absorb nutrients and germinate seeds. In fall, each plant sends up one leaf from a corm. The oval leaf is green on top, sometimes with raised purple spots, and has a deep purple underside. The leaf stays green over the winter and then disappears in spring. In early summer, a single stem rises out of the leaf litter to be 15–20 inches tall. In July–August, up to 55 small, delicate light purplish-greenish blossoms appear, resembling a group of craneflies hovering around the stem. These flowers attract nocturnal moths, which pollinate the flowers by brushing their eyes against a specialized structure containing pollen.

Continue along the Upland Walk and take a right on South Tuckahoe Valley Trail. The next orchid ID markers are for the pink lady's slipper (Cypripedium acaule) that bloomed in May. Farther ahead on this trail is the downy rattlesnake plantain orchid (Goodyera pubescens), which we talked about last month. This orchid blooms in July–August. There is no ID marker, so look carefully about 10–15 feet to the left after an S turn in the trail. If you reach a series of small decks after which the trail narrows noticeably, you will have gone too far. This orchid likes acidic sandy loam soil in deciduous and coniferous forests. Growing in the leaf litter almost flat to the ground, its evergreen leaves form a small, showy dark green rosette with striking white veining, resembling snakeskin. The single flower stalk appears in May–June, and small, fragrant white blossoms, densely packed along the top part of the stem, open in July–August. These orchids often grow in a colony with several blooming. They are pollinated by native bees.

As you continue your walk, keep looking and observing. What else can you find to sketch?

Diane DuBois Mullaly

Fine artist/Maryland Master Naturalist

Build a House for The Great Fairy House Challenge!

Fairyfest returns to the Arboretum on October 1! This year, get ready by building an entry for The Great Fairy House Challenge. Houses will be on display from late September to October 15 and will be vital in lending an air of whimsy and magic to the Fairyfest event and to our enchanted forest paths.

The theme of your fairy house can be anything you wish, and you can find the rules and submission form here. Awards will be given in four separate categories. 

Please let Jenny Houghton know by Saturday, September 10 of your intention to participate. You can reach her by email or at 410-634-2847, ext. 23.

Photo by Kellen McCluskey


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