Leader
for today’s Ramble: Kaitlin Swiantek and Catherine Chastain
Authors of today’s Ramble report: Linda and Don. Comments, edits, and suggestions for the report can be
sent to Linda at Lchafin (at) uga.edu.
Insect and fungi identifications: Don Hunter, Heather Larkin, Bill Sheehan
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 a mouse or tapping on your screen.
Today’s emphasis: Pollination of native plants
and cultivars
Catherine
invited Kaitlin Swiantek, a grad student in horticulture at UGA, to speak to us
about her project and to walk with us through the International, Heritage and
Flower Gardens, sharing her observations about pollination issues,
including selection of insects capable of pollination based on both flower
structure and insect anatomy, among other things. She is studying several
species of Mountain Mint in the genus Pycnanthemum for their commercial potential for use in home and business landscaping as a way to support
pollinators. Currently, there are only a few species available on the market: Pycnanthemum
muticum, P. verticillatum, and P. virginianum.
Left to right: Pycnanthemum muticum, P. verticillatum, and P. virginianum photo credits: Don Hunter, Kerry Woods, Alan Cressler |
Announcements/Interesting
Things to Note:
The
Botanical Garden’s Fall Native Plant Sale begins this Thursday! Here are the
days and hours that plants will be available: Thu-Sat, Oct 5-7 and Thu-Sat, Oct 12-14. Thursdays and Fridays: 4-6pm. Saturdays: 9am-noon.
For a list of species available for sale, email Linda.
Roger
Nielsen was applauded for receiving a Sandy Star Award at the annual Sandy
Creek Nature Center members’ meeting in recognition for the work he
has done through the years at the nature center.
Roger
also announced that recorded interviews with founders, past
staff, and significant contributors to the Nature Center are archived at UGA’s
Hargrett Special Collections Library and can be heard here. They
can also be heard on the Nature Center website here.
Terry
mentioned that Margaret Renkl, author of “Late Migrations” (2019) and “The
Comfort of Crows, A Backyard Year” (2023) will be speaking at the Athens-Clarke
County Library, October 16th, at 7:00pm
Gary reported that today, September 28, is “Good Neighbor
Day,” designated by Jimmy Carter during his presidency. Coincidentally, Carter’s
99th birthday is this Sunday, October 1. To celebrate his birthday,
Creature Comforts is releasing a new beer, Beautiful Mosaic, an IPA named for a
remark made by Carter: “We have become not a melting pot but a beautiful
mosaic. Different people, different beliefs, different yearnings, different
hopes, different dreams.”
Reading:
Catherine read from “Thirteen
Moons on Turtles’ Backs, a Native American Year of Moons,” written by Joseph
Bruchac and Jonathon London, and illustrated by Thomas Locker.
Moon of Falling Leaves
Long ago, the trees were told
they must stay awake
seven days and nights,
but only the cedar,
the pine and the spruce
stayed awake until
the seventh night.
The reward they were given
was to always be green,
while all the other trees
must shed their leaves.
So, each autumn, the leaves
of the sleeping trees fall.
They cover the floor
of our woodlands with colors
as bright as the flowers
that come with the spring.
The leaves return the strength
of one more year’s growth
to the earth.
This journey
the leaves are taking
is part of that great circle
which holds us all close to the earth.
Show
and Tell: A rambler brought a twig of Yaupon Holly with leaves that appeared diseased, wondering if
the cause is a pathogen or an insect. No one knew that answer. Shown this photo later in the week, rambler and
plant pathologist Elizabeth Little had this to say: “I cannot say positively the cause without
more info. Possibly herbicide (chemical) uptake but does not look typical of glyphosate
drift damage…Anther possibility is eryophyid mites (my best guess) or another
tiny sucking insect. The mites feed in growing buds causing growth abnormalities. They are a sporadic problem and are not harming the plant. (Please no insecticide! Would
not work on this type of insect anyway, and causes more harm than good, and may not be the cause). Does not appear to be disease. Does not look viral.
There are no known significant disease or insect problems on Yaupon Holly. Plant
should be fine. See how it buds out in the spring.”
Today’s
Route: We headed down to the Flower
Bridge, making our way through the China and Asia Sections to the Threatened and
Endangered Plant garden. From there, we passed through the Physic Garden and
Heritage Garden, and down the steps into the Flower Garden. From there we took
the Purple Trail/Flower Garden Connector trail to the Purple Trail, which we
took back up the Visitor Center.
Bumblebee visiting a flower of Blue Salvia. |
On the Flower Bridge, Kaitlin focused on the Blue Salvia
in the planters, reporting that, in her study gardens, she sees carpenter
bees mostly nectar robbing since they are too large to enter many flowers. On
the other hand, bumblebees are generally small enough that they can access the
nectar directly by crawling inside the flower, thereby pollinating the flowers.
Left, Camellia flower with a single whorl of petals and right, a “doubled” flower with 3 or 4 whorls |
Kaitlin
also commented on the problem of developing cultivars with showier flowers. An
example is the creation of “doubles” with twice or more of the natural number
of petals. For example, a wild Camellia flower has five petals in a single whorl, but a “doubled” Camellia has many whorls, each with many petals. The changes in flower anatomy result in sacrificing
reproductive features, such as stamens that normally produce pollen, or pistils which
receive and transmit pollen to the flower’s ovules. Both stamens and pistils can be induced to change into petals. Even nectar-producing structures
may be sacrificed to create more or larger petals. These extra-showy flowers
may briefly attract pollinators but the insects may learn that there’s nothing
to be found in these flowers and ignore them. And – a double-whammy for wildlife
– these flowers will not produce seeds. “Doubling” is now usually achieved by manipulating the genes that affect petal, stamen, and pistil formation. Before the era of genetic manipulation, nurserymen watched for natural mutations among their plants and propagated those they found desirable, with the same impact on pollinators.
Ovate Catchfly is flourishing in the Threatened and Endangered Species section of the International Garden. This species is rare throughout its range (Georgia, north to Virginia and west to Arkansas and Mississippi) and is considered imperiled in Georgia. There is a small wild population located in Athens in Ben Burton Park. Its flowers have five white petals that are about ½ inch long, each deeply divided into eight segments. |
Linda picked up a small branch in
the T&E section to use as a “Joro stick” – Bill realized that the stick had
already been put to a much more interesting use.
Covered with Brown-toothed Crust fungi, the stick is home to a large number of galls created by an as yet unnamed midge whose larvae eat the fungi. |
Close-up of a dissected gall – the hollow portion was occupied by a larval midge, now emerged. Last time we saw these galls, in May, Bill took some home and raised the midges in captivity. Photos of the midges can be seen here (scroll down). |
Cone-like |
Giant |
Two weeks ago, Ramblers examined the
Northern Prickly-ash shrub in the Physic Garden and watched as Giant Swallowtail caterpillars
consumed the foliage on the tree. Today, we saw that the defoliation was nearly
complete and that the caterpillars have resorted to eating the thin, reddish-brown
bark on the twigs. We found two caterpillars remaining on nearby vegetation. Heather
said she has been visiting the tree every three days since our last visit here
and that she witnessed the transformation to pupae that dropped from the tree
and made their way into the duff surrounding shrubs.
Twigs scraped of bark by Giant Swallowtail caterpillars. |
Narrow-leaf Sunflower planted in front of Longleaf Pines at the gazebo in the Heritage Garden |
Ramblers asked the difference
between Narrow-leaf and Appalachian Sunflowers, and Linda pointed out the
narrow, single-veined leaves of the former and described the wider, oval leaves
of the latter. Both species’ leaves are very rough and sandpapery to the touch.
Narrow-leaf occurs throughout Georgia, Appalachian mostly in the mountains with
some populations in the upper Piedmont. Someone else asked about the range of Longleaf
Pines in Georgia. They are primarily found in the Coastal Plain, but there is a
“montane” form of the same species that occurs in the Ridge & Valley region
of northwest Georgia and south into the western Piedmont on Pine Mountain and nearby
ridges, as well as in adjacent northeastern Alabama.
The Indigo plants in the Heritage Garden’s Indigo bed are now in fruit. |
Indigo production was a major source of income during
colonial days in both Georgia and South Carolina. Producing indigo dye was a dangerous
and disgusting process relegated to enslaved laborers. The New Georgia
Encyclopia’s article on Indigo described the process during
pre-Civil War years: “The noxious stench associated with processing indigo is
well documented. The fermenting liquid smelled so foul that processing
facilities were always located well away from dwellings. Long-term exposure to
the vapors given off by fermentation, oxygenation, and precipitation, as well
as the presence of disease-carrying insects, may explain why the life span for enslaved
workers involved with indigo processing has been reported to have been a mere
five to seven years.” Indigo dye derived from plants has
been largely replaced by synthetic dyes but you can watch the process of
producing the dye by hand in modern Thailand here.
Entering the Flower Garden, we were struck by the sweet smell of the Tea Olive in full flower. This particular cultivar bears peach-colored flowers. |
Ramblers gathered around Catherine and Kaitlin in the middle of the Flower Garden where Kaitlin told us about her efforts to document the diversity of pollinators seen on different plants. |
Kaitlin
began her pollinator research by learning to identify the insect pollinators
that visited her Mountain-mint plants. At first, she used the broad categories
of insects (Bumble Bees, Honey Bees, Small Bees, Carpenter Bees, Wasps, Flies,
Butterflies/Moths, Other
insects) used by the Great Georgia/ Southeast Pollinator Census. Eventually,
she refined the identification process with the help of UGA entomologists, learning
to identify the insects to family or genus. Her observations sometimes required
captures, either directly with nets, or, for the smaller insects, the use of aspiration,
where the insect is sucked through a flexible tube into a collection bottle.
Kaitlin Swiatek |
Catherine asked Kaitlin about underappreciated
pollinators – it’s not all about bees and butterflies. Kaitlin mentioned moths,
which we don’t normally see in the daylight hours, as well as flies,
particularly the little sweat bees and hover flies.
Clearwing Moth photographed in 2017 by Don in the Physic Garden |
Moth Mullein with its fancy colorful stamens in the middle of the white flowers – the stamens’ filaments are covered with purple bristles and the anthers are orange. |
Linda was surprised to discover a Tamarisk shrub in the Flower Garden. This globally invasive plant has degraded riparian zones throughout the American southwest and other arid areas globally, where it “displaces native plants, drastically alters habitat and food webs for animals, depletes water sources, and increases erosion, flood damage, soil salinity, and fire potential.” |
Winterberry, a native holly species, in fruit Although its native habitat is wetlands, it appears to thrive in upland gardens. Its long-lasting fruits provide birds with late winter food. |
We returned to the Visitor Center
via the Purple Trail and were again struck by the number of downed and dead trees,
mostly Northern Red Oaks. Some were recently fallen, some older, but most appeared
to have died in the past few years. Northern Reds are at the very southernmost
edge of their range in the Georgia Piedmont and seem to be falling victim to
the increased temperatures and severe storms predicted by climate change
researchers for our area. Even a cursory survey of the forest floor reveals
that these old Northern Reds are not being replaced with Northern Red seedlings and saplings. The
large herds of deer that now roam the Garden’s forests are largely to blame for
that, but research conducted at Whitehall Forest, UGA School of Forestry, suggests
that frequent heat waves also impact Northern Red Oak seedlings. The
researchers exposed seedlings to consecutive heat waves and found that
they have lower rates of photosynthesis both during and between the heat waves,
and thus have lower survival rates.
Victoria asked for a look at a hickory tree so the ramble ended with a search for a trunk with conspicuously braided bark. A Mockernut Hickory was finally spotted near the top of the Purple Trail. |
SUMMARY OF OBSERVED SPECIES:
Blue Salvia Salvia sp.
Eastern Bumble Bee Bombus
impatiens
Ovate Catchfly Silene ovata
Brown-toothed Crust Fungus Hydnoporia
olivacea
Hops Humulus lupulus
Northern Prickly-ash, Northern Toothache-tree Zanthoxylum americanum
Eastern Giant Swallowtail (caterpillar)
Papilio cresphontes
Narrow-leaf Sunflower Helianthus
angustifolius
Longleaf Pine Pinus palustris
Big Bluestem Andropogon gerardii
Star-of-David Okra cultivar Abelmoschus
esculentus
Squash Bug Anasa tristis
Indigo Indigofera tinctoria
Sweet Tea Olive Osmanthus fragrans
White Gaura (Bee Blossom) Gaura sp.
Moth Mullein Verbascum blattaria
Tamarisk cultivar ‘Pink Cascade’ Tamarix
ramosissima
Winterberry Ilex verticillata
Obedient Plant Physostegia
virginiana
Purple Foxglove Digitalis purpurea
White Oak Quercus alba
Possumhaw Holly Ilex decidua
Horse Sugar Symplocos tinctoria
Mockernut Hickory Carya tomentosa