Leader for today's Ramble: Heather
Authors of today’s Ramble report: Linda, Heather, Don. Comments, edits, and suggestions for the report can be sent to Linda at Lchafin@uga.edu.
Link to Don’s Facebook album for this Ramble. All
the photos that appear in this report, unless otherwise credited, were taken by
Don Hunter. Photos may be enlarged by clicking them with your mouse or tapping your screen.
Number of Ramblers today: 21
Today's emphasis: Frost flowers and other frosty things in the prairie and floodplain
Announcements/Interesting Things to Note:
Bob Ambrose will give the featured presentation at the next “Word of Mouth Open Mic,” Athens’s longest-running spoken word event, on November 2nd, at The Globe in downtown Athens. The event starts at 7:00 with Bob's presentation beginning at 7:30. The theme is “What Haunts the End of the Anthropocene.” Bob writes: "I have prepared a set of nine poems that address the effects of humankind on the living world, personified as Gaia. Using biblical rhythms and modern scientific understanding, the set amounts to a prophesy, or warning, of a future that could still be avoided." Lists and links to the poems Bob will be reciting are on his webpage.
Richard extended an invitation to a garden walk and wood-fired pizza oven dinner at his place on November 13th at around 4:30 p.m. He will send out details on the Facebook Nature Rambling group page.
The student farmer's market at the UGarden continues every Thursday from 4:30-6 pm. All products are grown at the farm using organic practices, and all proceeds go to fund operations at the farm to provide fresh produce to families in need in the local community. 2510 South Milledge Ave., first driveway on the right (if you are coming from the Loop) after the Bot Garden entrance.
Today's
Route: Hoping to catch the frost flowers before the sun topped the trees, we hurried down the entrance road to the right-of-way, and explored both north and south of the road, in the Nash Prairie, the new prairie, and the floodplain. We then took the long way home on the White Trail, walking upstream along the river to the Mimsie Lanier Center, then returning to the parking area along the entrance road.
 | |
| Sun rising over the trees along the right-of-way prairie. Photo by Linda Chafin |
Now constantly there is the sound,
Under their loosening bright
Now the only flowers
The calling of a crow sounds
-from "New Collected Poems," Counterpoint, 2012.
 |
| Clasping Aster |
OBSERVATIONS:
Frost and ice crystals were on order for today’s ramble, so a little background on these sometimes misunderstood words is called for. Frost forms when “water vapor in an above-freezing atmosphere comes in contact with a solid surface whose temperature is below freezing,” per Wikipedia. In other words, frost is not frozen dew, as I’ve always thought; it is water vapor (a gas) that passes directly to ice (a solid), without ever going through a liquid phase. Generally, frost forms on a surface only when that surface “is colder than the surrounding air,” which accounts for why we may see lawns and fields covered with frost when the air temperature is above 32 degrees, something that I’ve long wondered about. This is especially true in low-lying areas because cold air drains downslope and forms pools of colder temperature. As an example, during the ramble we found frost flowers only on plants growing on the lower slope of the right-of-way prairie.
A term I was throwing around (probably inaccurately) on Thursday – rime – is defined as ice that "forms when super-cooled water droplets freeze onto surfaces.…It is not a type of frost, since usually water drops are involved [in rime formation]... Unlike hoar frost, which has a feathery appearance, rime generally has an icy, solid appearance.” I’m not sure if the ice formations we saw on leaves and flowers are frost or rime ice, or maybe some of both.
Another cold-weather phenomenon – frost flowers – has been a favorite of ramblers for years. Dale wrote about frost flowers in a November 2015 nature ramble report. The following is an excerpt from that report, though I recommend you read his entire essay, here:
“How frost flowers form: The water in the soil enters the root system by a process called osmosis. Osmosis is the term describing the movement of water across a cell membrane from a more dilute solution to a more concentrated solution. In this case the more concentrated solution is the sap in the root system and the less concentrated solution is the water in the soil. This movement of water into the root causes the sap in the plant's conductive tissues to rise. If the stem above has been injured or has a weakened skin the water will ooze out at the damaged spots. When the temperature is low enough this oozing water will freeze, beginning a frost flower. This 2013 article by James R. Carter in the American Scientist magazine is the best discussion I have found on how such lovely and delicate features form. In his article, Carter also mentions a Georgia connection to the phenomenon:
‘. . . physician and naturalist John LeConte of the University of Georgia made many insightful observations about whole and cut-off stems, both of which grew ice. He noted that many plant stems were dead and dry at the time of year when he did his study, although the roots might have been alive, but the ice formation therefore didn’t seem to be connected to the plant’s physiological functions. He observed, “At a distance they present an appearance resembling locks of cotton-wool, varying from four to five inches in diameter, placed around the roots of plants; and when numerous the effect is striking and beautiful.’
We were dismayed to find the right-of-way newly shorn of vegetation in many places. Georgia Power crudely trimmed the trees along the forest edges and removed the Dogwoods in the Nash Prairie. They also mowed the areas below the road that are dominated by White Crownbeard – the source of frost flowers – so we didn’t see as many as expected. However, Don managed to capture some wonderful images of this phenomenon – here's a gallery of his frost flower photos from Thursday. Photos may be enlarged by clicking them with your mouse or tapping your screen.
Once we reached the floodplain, Heather alerted us to the icy spectacles to be seen at high magnification – icy cubes, fans, and rods adorning the surfaces and margins of leaves, petals, stems, thorns, and hairs of plants in the right-of-way. Below is a selection of her amazing macro photography. Photos may be enlarged by clicking them with your mouse or tapping your screen.
Don also captured the intricate beauty of ice and frost in the photographs below. Photos may be enlarged by clicking them with your mouse or tapping your screen.
 |
| Ground Ivy |
 |
| Virgin’s Bower seed heads |
 |
| Tall Goldenrod flower heads |
 |
| Splitbeard Bluestem spikelets |
 |
| Horseweed seed heads |
 |
| Deer-tongue Witch-grass leaf sheaths |
 |
| Common Wingstem leaf surfaces with galls |
 |
| Carolina Horse-nettle thorns |
 |
| Carolina Horse-nettle |
As the sun rose above the tree line, frost and ice turned to water, and we left the right-of-way and headed upstream along the Middle Oconee River on the White Trail, stopping first at the River Cane stand to examine two species of vines, one exotic and one native, twining through the thicket of cane stems.
 |
| Chinese Yam, an invasive exotic vine also called Cinnamon Vine, is in the yam family though not related
to sweet potatoes (which are in the morning-glory family). It reproduces primarily by the spread of the pictured bulbils, which fall to the ground and sprout at the conspicuous "eyes," similar to white potatoes (which are in the deadly nightshade family). |
 |
| Fruits of Small White Morning-glory, a native climber |
Several
species in the Aster/Composite family are still in flower along the White
Trail.
 |
|
Fall is Purple Aster season in the Piedmont,
from left to right: |
Several large Common (or Mountain) Silverbell trees occur in this stretch of the White Trail, including one that may be the record-sized tree for Clarke County.
 |
|
Common Silverbell
bark is distinctively striped on immature trees and branches (left, photo by
Will Cook) and on purple-tinted mature trunks |
 |
| Gary provides scale for a large-diameter Common Silverbell. |
 |
| Virginia Tiger Moth caterpillar, also known as Yellow Woolly-bear |
Typically, two generations of woolly caterpillars hatch from eggs during the summer, spin their cocoons, and emerge as adult moths in a single year. A third generation may hatch in the fall and overwinter as caterpillars, sheltering in wood piles or leaf litter. Humans usually don’t notice these animals until they become conspicuous in the fall while they are searching for shelter. They survive the winter by producing a sugar-rich anti-freeze in their “blood” (actually hemolymph) that reduces the freezing point of their bodily fluids. Next spring, these caterpillars will leave their shelters, spin cocoons, and emerge in a couple of weeks as Virginia Tiger Moths, ready to mate, lay eggs, and start the cycle all over again.
 |
| Virginia Tiger Moth (photo by Andy Reago and Chrissy McClarren) |
 |
| The white-fruited variety of the native American Beautyberry is
apparently the result of a natural mutation and is now widely available in the nursery
trade. Birds relish the magenta fruits of the species; it’s unknown if birds eat the white fruits of this variety. |
 |
| Carolina Coralbead fruits |
 |
| Carolina Coralbead twining up a pine sapling. It’s never too soon to start decorating for the holidays. |
 |
| Pine Webworm Moth
caterpillar nest made of frass and silk held on a branch of a young Loblolly Pine. |
OBSERVED SPECIES:
White Crownbeard Verbesina virginica
Splitbeard Bluestem Andropogon ternarius
Horseweed Conyza canadensis syn. Erigeron canadensis
Common Wingstem Verbesina alternifolia
Ground Ivy Glechoma hederacea
Dotted Smartweed Persicaria punctata
Deer-tongue Witch-grass Dichanthelium clandestinum
Tall Goldenrod Solidago altissima
Carolina Horse-nettle Solanum carolinense
River Cane Arundinaria gigantea
Small White Morning Glory Ipomoea lacunosa
Chinese Yam, Cinnamon Vine Dioscorea polystachya
Blue-stem Goldenrod Solidago caesia
Curtis’s Goldenrod, Mountain Decumbent Goldenrod Solidago curtisii
River Oats Chasmanthium latifolium
Mock Orange Philadelphus inodorus
Chinese Privet Ligustrum sinense
Common Silverbell, Mountain Silverbell Halesia tetraptera
River Birch Betula nigra
Perilla Mint Perilla frutescens
Virginia Tiger Moth Spilosoma virginica
Virgin’s Bower Clematis virginiana
Georgia Aster Symphyotrichum georgianum
Clasping Aster, Late Purple Aster Symphyotrichum patens
Michaux’s Sumac Rhus michauxii
Smooth Sumac Rhus glabra
American Beautyberry (white form) Callicarpa americana var. lactea
Loblolly Pine Pinus taeda
Carolina Coral-bead Cocculus carolinus
Pine Webworm Moth (caterpillar nest) Pococera rubustella
Postscript: Botanical gardens act as artificial oases for butterflies in arid urban areas.
Postscript: Wait, why are there so few dead bugs on my windshield these days?
