Leader of Today’s Ramble: Linda Chafin
Authors of Today’s Report: Linda Chafin, Don Hunter
The photos that appear in this report were taken by Don Hunter unless otherwise credited. Photos may be enlarged by clicking them with a mouse or tapping on your screen. Not all of Don’s photos from today’s ramble made it into the Ramble Report, so be sure to check out his Facebook album at this link.
Nature Ramble Rainy Day Policy: We show up at 9:00am, rain or shine. If it’s raining, we will meet and socialize in the conservatory (bring your own coffee); if there is a break in the rain, we’ll go outside and do a little rambling.
Today’s Emphasis: Late summer wildflowers, fruits, butterflies, and caterpillars in the floodplain.
Announcements:
Catherine mentioned a BBC article describing a project in East Sussex, England, where dogs are reseeding native species by romping around in a wildlife restoration area while wearing seed pouches.
And speaking of dog seeding activities… Gary brought up the topic of a new-to-Athens invasive plant species, Japanese Chaff Flower, Achyranthes japonica. It’s been consuming Atlanta parks for years and is now established in Athens at Memorial Park. We need to be vigilant in identifying this plant where we see it (here are some good photos and info). If we see it, we should notify the Ecological Resources Coordinator in the Athens/Clarke County Sustainability Department, Stephanie Green, 706-613-3838 ext. 6136 or stephanie.green@acc.gov. Much of this invasion is believed to be due to dog walkers and dogs – Chaff Flower seeds readily stick to fur and clothing. The county is considering a public outreach program targeting popular dog walking locations with information signs.
Show and Tell: Don brought a branch of American Burnweed (also known as Fireweed), a ubiquitous native weed spread far and wide by its wind-dispersed seeds this time of year.
Like other members of the Aster (Composite) Family, Burnweed holds its flowers in tightly packed heads. In Don’s photo, left, there is an unopened head in the background and a fully opened head up front. Yes, fully opened – there are no ray flowers and the head expands only when the seeds are ready to disperse, below.
Burnweed seed head dispersing hundreds of plume-tipped seeds. Photo by Hladac, Wikimedia Commons.
The stems of Burnweed are visited by a female Burnweed Gall Midge, a tiny insect who lays her eggs only in the stems of Burnweed, inducing the formation of a swollen gall.
Burnweed leaves are also visited by leaf miner insects that deposit their eggs between the upper and lower layers of leaf tissue. The narrowest end of the trail is the point where the leaf miner female laid her egg. Once the egg hatches, the ever-enlarging larva carves an ever-widening trail as it travels the leaf, eating everything in its path. In Don’s photos, you can see that the larva traveled the length of the leaves three times as it ate and grew. What is most amazing is that this is all taking place in the incredibly narrow space inside the leaf – a cramped but safe hideout from predators. At some point, the larva metamorphoses into an adult which then exits the leaf through a tiny hole it chews through the leaf surface, visible as a dark spot on the leaves in the photos above.
Reading: Linda read “Summer Is Losing Its Grip,” from Middlewood Journal: Drawing Inspiration from Nature, a Journey into the South Carolina Piedmont Woods by artist/essayist Helen Scott Correll.
I can tell summer is losing its grip. It’s interesting to note that I understand more every year that the seasons, which I used to consider fairly distinct, are really quite blurred. Painted Buckeye and Virginia Creeper leaves begin turning red as early as July: fuzzy spring-like oak leaves sprout until frost. During this morning’s ramble I saw the first “fall” Silvery Aster bloom for the year, and the Grass-Leaved Golden Asters, which have been blooming for a couple weeks. Thoroughworts aka Bonesets are in bloom, but fading. Tall Goldenrods already brighten the woodland edges. Joe Pye Weed and Pale Indian Plantain are in full bloom down by Meetinghouse Creek.
While I drew, fall Field Crickets trilled in the field behind me, and a White-Breasted Nuthatch’s loud and nasal ank ank! ank ank! gave away his position as he walked head-first down the trunk of an oak looking for insects. I remember the bird’s name and differentiate him from the brown creeper, who also hops on tree trunks, by thinking what a “nut” the Nuthatch is to hop head-first straight down the tree. The way a Brown Creeper does it, starting at the bottom of the tree and spiraling up the trunk, seems so much easier. The name Nuthatch actually comes from the bird’s habit of wedging nuts into cracks in a tree bark, then whacking at it with his sharp bill to “hatch” the nut from its shell. A Pileated Woodpecker screamed several times close by. A breeze kicked up and stirred the leaves, eventually becoming a steadying cooling wind that persuaded me to stay a while, just to enjoy it.
Number of Ramblers Today: 27
Today’s Route: We left the Children’s Garden arbor, heading into the Lower Shade Garden toward an entrance road gate, where we turned left down the road. We walked along the Dunson Garden deer fence, eventually making our way out into the power line ROW, then walking down the ADA trail to the Middle Oconee River. Here, we turned right (upstream) and walked for a short distance on the White Trail before turning around to head back.
Today’s Observations:
Two Daddy-long-legs are exploring the spent flower heads of a Rattlesnake Master in the Children’s Garden.
A Common Eastern Bumblebee nectaring at a flower cluster in the Hoary Mountainmint near the Children’s Garden Arbor. Note the pollen grains stuck to the hairs on its thorax and abdomen.
From Bees and Flowers Harness Static Electricity to Spread Pollen: “When a bee flies through the air, it generates a positive electrostatic charge. This charge arises due to the friction between the bee and positively charged particles in the atmosphere. Flowers, on the other hand, function as part of the Earth’s surface and typically hold a slight negative charge. This charge is concentrated at…the tips of petals, the pollen-carrying stamens, and the ovary-containing pistils of the flowers…As a bee approaches a flower, the difference in charge causes antennae and tiny hairs to flutter, which the bee detects as a physical sensation (interestingly, honeybees respond to the motion of their antennae, while the fuzzier bumblebees respond to sensation from the hairs). When the bee approaches a flower, the electrical interaction becomes even more dynamic. The pollen, being negatively charged with the rest of the flower, is attracted to the positively charged bee and leaps across and sticks. When the bee visits the next blossom, some of the now positively charged pollen leaps across to the negatively charged pistil and begins the process of fertilization.”
Aubrey inspects the large Virginia Creeper vine that inhabits a Loblolly Pine in the Lower Shade Garden. It has long since detached its delicate suckers from the tree’s bark at the lower end. No one knows if bats actually use the bat house attached to the tree; there is no guano present, so probably not.
Several plantings of Golden Surprise Lily, also called Hurricane Lily, are in flower. These names reflect the fact that the flower stalks appear mysteriously without leaves in late summer and early fall, just in time for hurricanes. Their leaves appear only after flowering is over and persist til spring when they disappear. The bulbs then go dormant till hot, dry summer weather triggers blooming. For cultivation info, click here.
A Red-femured Orbweaver spider in a web beside the Lower Shade Garden path
Though uncommon in our mostly acidic Piedmont soils, Carolina Buckthorn can be abundant in soils with higher pH. It is an important wildlife species, acting as host for several butterflies: Gray Hairstreak, Painted Lady, Spring Azure, and Henry’s Elfin. The red berries are eaten by many species of birds. The Buckthorn family is largely tropical with only a handful of species, including Rattan-vine and New Jersey Tea, appearing in Georgia.
American Beautyberry with its berries clustered around the stem at each leaf node
Its berries are eaten by a variety of small mammals, including possums, raccoons, and squirrels. More than 40 species of songbirds are known to eat the fruit.
Silky Dogwood is planted in the Dunson Garden and spills out into the edge of the road, offering its blue fruits to birds. A late nymph stage Eastern Leaf-footed Bug is exploring these fruits. Leaf-footed Bugs are considered a major pest in fruit orchards and vegetable gardens; adults probe deep into fruit with their long, piercing-sucking mouth parts to extract water and sugars. Even the nymphs are able to pierce the skin of fruits. Fruit discolors and rots where the insect pierces the skin.
Bill spotted a recently named gall species that inhabits the branches and twigs of dogwoods. Each of the swellings is a separate chamber containing a single larva. Photo by Bill Sheehan
Eastern Anglepod is a milkvine in the same family as milkweed. Its fruit, left, is suspended from a vine that has climbed the Dunson Garden fence. Like milkweeds, milkvines have plumed seeds dispersed by the wind, below (photo credit: Alana Walker).
The Passionflower vines on the Dunson Garden fence are a great place to see all the stages in the life cycle of Gulf Fritillary butterflies. We didn’t see any eggs today, but did see many very small to large caterpillars that were eating their way through the leaves, left. Right, a caterpillar has just begun to pupate, hanging upside down, curling into the characteristic J-shape, and laying down some chrysalis silk.
Butterflies are not the only insects to enjoy Purple Passionflower vines. Ants help themselves to nectar produced by the extrafloral nectaries (EFNs – nectaries not inside a flower) found on the leaf stalks. They also attack caterpillars, reducing the amount of damage to the leaves.
Two Morning Glory vines grow on the Dunson Garden fence, Small White Morning Glory, left (click to enlarge), which has both white and lavender flowers, and Red Morning Glory, its corolla speckled with grains of white pollen.
Spotted Beebalm is still blooming. The pink bracts attract pollinators and the maroon dots on the yellow petals guide the insect, often a Carpenter Bee, to the nectary at the base of the flower tube.
American Wisteria (left) growing on the split rail fence in the right-of-way is heavily infected with Powdery Mildew (right). Rambler and plant pathologist Elizabeth Little writes: “Powdery mildew is an easily recognizable plant disease. Unlike other fungal plant parasites, these fungi grow mainly on the plant surface, creating a dense gray to white mat easily seen with the naked eye. Feeding structures called haustoria (see drawing below) grow into the live plant cells and extract nutrients without killing the cell. Each powdery mildew fungal species can only infect a specific genera or species of plant and do not cross infect other types of plants. While the fungus can be an important problem in some agricultural crops, in the garden the disease does not usually cause enough damage to warrant treatment. The fungi prefer warm and humid weather, but frequent rain will reduce infections. This year has had ideal conditions for development. Adequate sun and good air circulation will reduce infections. Resistant varieties are available for some plants such as cucurbits.”
Drawing of microscopic view of Powdery Mildew by Lenore Gray.
The Aster family dominates the view of the floodplain right-of-way in late summer and early fall. Four genera rule: Wingstem, Ironweed, Sunflower, Boneset, and Goldenrod (Verbesina, Vernonia, Eupatorium, and Solidago).
Three species of Wingstem, also known as Crownbeards, are common in the right-of-way. All are in the same genus – Verbesina. A Peppered Jumping Spider lurks amongst the flower heads of White Crownbeard (above, right). Also known as Frost Flower, this species produces beautiful frozen shapes from fissured stems during below-freezing nights in late autumn.
Yellow Crownbeard (left) and Common Wingstem (right) have similar flower heads, growth habit, and leaf shapes. The easiest way to distinguish them is leaf arrangement: Yellow Crownbeard’s leaves are in pairs and Common Wingstem leaves alternate around the stem.
Tall Ironweed’s flower heads lacks the ray flowers that most Aster Family species have. It makes up for it with showy, brilliantly colored disk flowers.
All species in the Aster family have flower heads surrounded at the base by one to several series of small overlapping bracts called phyllaries. In the case of Tall Ironweed, there are 4 or 5 series of bracts, each outlined in red and with spreading hairs along the edges.
Rough-leaf Sunflower is one of 24 species of native sunflowers in Georgia. It is tall, up to 6 feet, with smooth, often waxy stems. The flower heads have yellow disk and ray flowers. Its leaves are opposite with inch-long stalks, and are conspicuously three-veined and very roughly hairy, almost like sandpaper to the touch.
Late Boneset, with its snowy-white flower heads, is abundant in nearly all the sunny openings in the Garden.
Tall Goldenrod, often more than 6 feet tall, is ubiquitous in the Piedmont, spreading aggressively on roadsides and in other disturbed areas. Its flower heads have 8-13 ray flowers, and its leaves are roughly hairy, distinctly three-veined, and sometimes toothed.
Bean Family plants are also at their peak of flowering and fruiting in late summer. One of the most interesting plants (to me) in the floodplain is a “bean” – Maryland Senna, above. A tall, branched shrub, it bears many yellow, five-petaled flowers in August and long, showy bean pods in September. Its leaves are compound, made up of 6-12 pairs of oval leaflets. Near the base of the leaf stalk, is a very small, green or brown bump – an extrafloral nectary serving the same defensive function as the EFN’s on Passionflower leaves. Ants swarm to these nectaries and, in their spare time, attack the caterpillars of Sulphur butterflies who lay their eggs on the leaves of Senna.
Maryland Senna flowers (above left) and fruits (above right) – note the ants swarming among the fruits. Caterpillars of Cloudless Sulphur (below, left, click to enlarge) and Sleepy Orange (below, right, photo by Heather Larkin).
After much ooh-ing and ahh-ing over the gorgeous caterpillars, we walked to the river and turned upstream along the White Trail for a short walk in the shade. Even though I’ve walked this route scores (hundreds?) of times over the last 45 years, Ramblers noticed two tree species I’ve missed: an American Basswood and a Sugarberry.
The American Basswood is on the river side of the trail, soon after the little bridge. Basswood has large, more or less heart-shaped leaves (above, left) that are easily mistaken for Red Mulberry’s. Basswood’s leaves are mostly hairless, especially this late in the season, while Red Mulberry’s are roughly hairy on the lower surface and somewhat hairy on the upper. A reliable distinguishing trait of Basswood is the ring of smaller trunks that surrounds the main trunk (above, right). These sprout from the root crown of the original trunk and can become quite large. Basswood flowers are loaded with nectar and the trees are famous “honey trees” in some parts of the country. American Basswood prefers rich, moist soils and therefore is usually found in floodplains in the Piedmont. In the mountains, it grows in moist coves and boulder fields. European species of Basswood are known as Linden and Lime Trees, names apparently derived from the proto-German Linde. While discussing the Basswood, we were serenaded by a White-eyed Vireo.
A young Sugarberry is established on the landward side of the trail, its trunk covered in the warty projections (above, left) that are characteristic of Sugarberry and the closely related species, Hackberry. Roger first spied this tree and bushwhacked through the undergrowth to examine its trunk (above, right).
Hackberry Petiole Galls are formed when a small Psyllid insect lays its eggs in the stalks (petioles) of Sugarberry and Hackberry leaves. Uninfested leaves do not fall from the tree in autumn, making it easy to spot the galls in the winter. Details here…
Hackberry Emperor butterfly caterpillars are beautifully camouflaged at this stage for surviving on Hackberry and Sugarberry leaves. Later, the caterpillars will turn brown and overwinter in rolled Hackberry and Sugarberry leaves. More info here…. (Photos by Bill Sheehan)
The banks of the Middle Oconee River are subject to serious erosion following our heavy winter rains. The dense root networks of Catbriar, River Oats, and other plants hold the riverbank soils in place.
Stinging Wood Nettle’s flower clusters, leaves, and stems are covered with long, brittle, pointed hairs (photo below). But it’s not the hairs that sting; it’s the liquid inside the hairs that does the damage. When brushed, the tips of the hairs break off and release a fluid that contains a witch’s brew of irritating compounds, including histamine, acetylcholine, serotonin, and formic acid, the same chemical that makes ant bites sting. Invertebrates aren’t harmed by the compounds and, though we may not love the stinging, we have to love the beautiful Red Admiral, Eastern Comma, and Question Mark butterflies that use nettles as a larval host plant.
Red Admiral caterpillars (below, right) roll Stinging Nettle leaves into a temporary shelter while they eat the leaf, leaving some frass behind when they move on to the next leaf (below, left). Caterpillar photo by Anita Gould.
Other cool insects we saw today…..
Nason’s Slug Moth seen on a Sugarberry leaf
Zabulon Skipper
A late instar Milkweed Tussock Moth having a very bad hair day.
Like Monarchs, these moth larvae feed only on milkweeds. More info here… Photo by Heather Larkin
An ant-mimic jumping spider in the genus Peckhamia
Photo by Heather Larkin
Common Angle Moth is in the Geometer Family, so called because the larvae seem to be measuring the earth as they hump along the ground, also earning them the nickname “inchworm.” They are often seen apparently suspended in space from a nearly invisible silk thread. Dale wrote about inchworms in the July 8, 2021 Ramble Report. Photo by Heather Larkin
Black Saddlebags is a species of skimmer dragonfly that occurs throughout North America. Photo by Bill Sheehan
SUMMARY OF OBSERVED AND DISCUSSED SPECIES
American Burnweed Erechtites hieraciifolia
Burnweed Gall Midge Neolasioptera sp.
Daddy Longlegs Order Opiliones
Rattlesnake Master Eryngium yuccifolium
Hoary Mountainmint Pycnanthemum incanum
Common Eastern Bumble Bee Bombus impatiens
Joro Spider Trichonephila clavata
Loblolly Pine Pinus taeda
Virginia Creeper Parthenocissus quinquefolia
Surprise Lily, Hurricane Lily Lycoris aurea
Red-femured Orbweaver Neoscona domiciliorum
Carolina Buckthorn Frangula caroliniana
American Beautyberry Callicarpa americana
Silky Dogwood Cornus amomum
Dogwood gall Neolasioptera cornicola
Eastern Leaf-footed Bug (nymph) Leptoglossus phyllopus
Florida Torreya Tree Torreya taxifolia
Eastern Anglepod Gonolobus suberosus
Gulf Fritillary (adult and caterpillar) Agraulis vanillae
Purple Passionflower Passiflora incarnata
Ant (on passionflower vine) Family Formicidae
Little White Morning Glory Ipomoea lacunosa
Red Morning Glory Ipomoea coccinea
Spotted Beebalm Monarda punctata
American Wisteria Wisteria frutescens
Powdery Mildew An ascomycete fungi in the order Erysiphales
White Crownbeard Verbesina virginica
Yellow Crownbeard Verbesina occidentalis
Common Wingstem Verbesina alternifolia
Tall Ironweed Vernonia gigantea
Late Boneset / Late Thoroughwort Eupatorium serotinum
Rough-leaved Sunflower Helianthus strumosus
Dog Fennel Eupatorium capillifolium
Virgin’s Bower Clematis virginiana
Red-tailed Hawk (heard) Buteo jamaicensis
Tall Goldenrod Solidago altissima
Maryland Senna Senna marilandica
Cloudless Sulphur (caterpillar) Phoebis sennae
Sleepy Orange (caterpillar) Eurema nicippe
False Nettle Boehmeria cylindrica
River Cane Arundinaria gigantea
Camphorweed Pluchea camphorata
Basswood Tilia americana
White-eyed Vireo (heard) Vireo griseus
Sugarberry / Southern Hackberry Celtis laevigata
Hackberry Petiole Gall Pachypsylla venusta
Hackberry Emperor butterfly (caterpillar) Asterocampa celtis
Catbriar Smilax bona-nox
River Oats Chasmanthium latifolium
Common Yellow Wood Sorrel Oxalis stricta
Stinging Wood Nettle Laportea canadensis
Red Admiral (larval shelter only) Vanessa atalanta
Nason’s Slug Moth (caterpillar) Natada nasoni
Zabulon Skipper Poanes zabulon
Milkweed Tussock Moth (caterpillar) Euchaetes egle
Ant-mimic Jumping Spider Peckhamia sp.
Peppered Jumping Spider Pelegrina galathea
Common Angle Moth (adult) Macaria aemulataria
Black Saddlebags Tramea lacerata