Ramble Report September 28, 2023

 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.

Number of Ramblers today: 35

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 16^th, at 7:00pm

Gary reported that today, September 28, is “Good Neighbor Day,” designated  by Jimmy Carter during his presidency. Coincidentally, Carter’s 99^th 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.

OBSERVATIONS:

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 inflorescence on the Hops vines growing on the Physic Garden arbor.

Golden-yellow glands are found at the base of the bracts that comprise female Hop “cones.” The glands are the source of the compounds that produce "hoppy" flavors in beer. These compounds also act as a preservative and promote a good head on a glass of beer.
Photo by Jan Coyne

Giant Swallowtail caterpillar consuming the last of the leaves on Northern Prickly-ash

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.

Big Bluestem grass is planted in the bed with Narrowleaf Sunflowers. Its seed heads have 3-5 spike-like branches forming a “turkey’s foot.” Don captured the unappreciated beauty of grass flowers in this photo: the orange dangling anthers and the purple bottle-brush stigmas. The anthers release their pollen into the wind, while the plume-like stigmas gather it. Grasses are self-incompatible: only pollen from a different plant will successfully pollinate a grass flower.

The Heritage Garden sports an unusual variety of Okra this year: 'Star-of-David,' an Israeli heirloom cultivar. The pods are larger and fatter than the pods on typical Okra. Someone spotted a Squash Bug (below) on one of the okra plants.

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

Gaura aka Bee-blossom in flower
Bee-blossom flowers have long floral tubes filled with nectar that is accessed by insects with long tongues such as bumblebees. Other species in this genus (Gaura or Oenothera) that bloom at night are pollinated by moths.

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.

Obedient Plant, a member of the Mint family, is another native wetland species that makes an excellent garden plant. Its flowers are pollinated primarily by bumblebees but are also visited by butterflies and hummingbirds.

Foxgloves, native to Europe and western Asia, are popular garden plants with their large, purple and white flowers in tall, erect spikes.The interior of their flowers is conspicuously dotted with nectar guides.

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