Thursday, April 4, 2024

Ramble Report - April 4, 2024

Leader for today's Ramble: Linda

Authors of today’s Ramble Report:
Linda and Don

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. 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.

There is now a Link to the 2024 calendar of the Nature Rambles and book group meetings on the upper right of your screen. This is a work in progress. Thanks to Bill for setting this up!

Today's emphasis:  
Looking for frog eggs and flowering Butterweed in the Middle Oconee River floodplain

Number of Ramblers today: 30

Today's Route: We left the Children's Garden and headed down the White Trail extension to the power line right-of-way, stopping to look for ephemeral pools. We then followed the ADA trail to the river and turned left on the White Trail, following it to the spur that crosses the floodplain and returns up the hill. We took the spur trail back to the White Trail and returned to the Children's Garden.

Announcements:

The April 18 ramble will be led by Catherine, who will lead us in another “art ramble.”  Please bring a clipboard if you have one. If you don’t, we will have a few spare ones. Also bring your creative spirit!

The April 25 ramble will be led by Bay Noland-Armstrong, a graduating senior in the Wildlife Resources Department in the Forestry School. She will teach novices how to bird and give experienced birders a chance to hone their skills during migration. Please bring binoculars if you have them; if you don’t, we will have a few spares on hand. Also, download the Merlin app available free from the Cornell Lab of Ornithology to your phone.

The Nature Rambler book group meets next on April 18 in the Adult Education Classroom in the Education Department in the Visitor Center at the Garden. Richard will moderate a discussion of The Life of a Leaf by Steven Vogel. 

The Garden has announced plans to re-route and convert the existing mulched trails in the Dunson Native Flora Garden to paved, ADA-approved trails. Comments on this proposed plan may be sent to the Garden’s Director, Jenny Cruse-Sanders (crusesanders@uga.edu) and the Garden’s Director of Horticulture, Jason Young (Jason.Young@uga.edu).

The Garden’s Spring Plant Sale is this week. There will be a Friends Pre-sale on Thursday, April 11, from 2:00 to 6:00 pm, with the general public welcome on Friday, 2:00 pm to 6:00 pm, and Saturday, 8:00 am to 2:00 pm.

Interesting follow-up article to this week’s solar eclipse. An eclipse is wondrous — don’t underestimate it.”

Show-and-Tell: 

Nathan brought a sample of Oriental False Hawksbeard, an exotic invasive species that has become incredibly widespread in just the last decade. Nathan recommends that we pull it up before it goes to seed, taking care to get as much of the root as possible. It’s a shallowly rooted plant and not hard to pull up. More info is here.

Today’s Reading:  Linda read an essay about a hummingbird building a nest from Barbara Kingsolver’s book Small Wonder.

“In the slender shoulders of the myrtle tree outside my kitchen window, a hummingbird built her nest. It was in April, the sexiest month, season of bud-burst and courtship displays, though I was at the sink washing breakfast dishes and missing the party, or so you might think. Then my eye caught a flicker of motion outside, and there she was, hovering uncertainly. She held in the tip of her beak a wisp of wadded spider web so tiny I wasn't even sure it was there, until she carefully smooshed it onto the branch. She vanished then, but in less than a minute she was back with another tiny white tuft that she stuck on top of the first. For more than an hour she returned again and again, increasingly confident of her mission, building up by infinitesimal degrees a whitish lump on the branch-and leaving me plumb in awe of the supply of spider webbing on the face of the land. When the lump had grown big enough  when some genetic trigger in her small brain said, "Now, that will do "she stopped gathering and sat down on her little tuffet, waggling her wings and tiny rounded under- belly to shape the blob into a cup that would easily fit inside my cupped hand. Then she hovered up to inspect it from this side and that, settled and waddled with greater fervor, hovered and appraised some more, and dashed off again. She began now to return with fine filaments of shredded bark, which she wove into the webbing along with some dry leaflets and a slap-dab or two of lichen pressed onto the outside for curb appeal. When she had made of all this a perfect, symmetrical cup, she did the most surprising thing of all: She sat on it, stretched herself forward, extended the unbelievable length of her tongue, and licked her new nest in a long upward stroke from bottom to rim. Then she rotated herself a minute degree, leaned forward, and licked again. I watched her go all the way around, licking the entire nest in a slow rotation that took ten minutes to complete and ended precisely back at her starting point. Passed down from hummingbird great-grandmothers immemorial, a spectacular genetic map in her mind had instructed her at every step, from snipping out with her beak the first spiderweb tuft to laying down whatever salivary secretion was needed to accrete and finalize her essential creation. Then, suddenly, that was that. Her busy urgency vanished, and she settled in for the long stillness of laying and incubation.”

Anna's Hummingbird in her nest
Photo by Steve Berardi

OBSERVATIONS:
Eastern Red Columbine flowering at the edge of the Children’s Garden
Flowering time of Red Columbine (and several other species such as Red and Painted Buckeyes) usually coincides with the arrival of Ruby-throated Hummingbirds, who fly across the Gulf of Mexico from their wintering grounds in Central America. Our native Eastern Red Columbine has a special relationship with hummingbirds: their red color is especially attractive to hummers and their nectar has twice the amount of sugar as western Columbines. Columbine flowers produce nectar inside the very tips of the “spurs” (modified petals) that point upward at the top of the flower. As hummingbirds probe for nectar, their foreheads pick up pollen from the flower’s stamens, pollen which is hopefully transferred to stigmas on the next plant they visit. Columbine is capable of producing viable seeds from self-pollination but repeated self-pollination within a plant population carries the risks of inbreeding: populations of plants with low genetic diversity are more vulnerable to disease and may lack the ability to respond to changing environmental conditions.

Piedmont Azalea is planted at the top of the paved path through the Lower Shade Garden.
Pollinators of native Azalea flowers were a mystery for many years. The nectar is produced deep inside the tubed portion of the flower, while the pollen-producing anthers at the tip of the stamens are held inches from the tube. Not to mention the pollen-receptive stigma, which protrudes even further than the stamens. How does an insect probing the tube come into contact with all three important parts of this system: the nectar glands, the anthers, and the stigma? North Carolina State University biologist Mary Jane Epps found out the answer which you can read about here.
A Pale Yellow Trillium in bud
In mid-March, the Lower Shade and Dunson Gardens are filled with flowering Sweet Betsy, Trailing (Decumbent), and Chattahoochee Trillium. A few weeks later, the Pale Yellow Trillium emerges and flowers. Like the Trailing Trillium and Chattahoochee Trillium, the Pale Yellow Trillium is not native to the Athens area but was planted in Dunson to make a microcosm of Georgia’s flora available to visitors. Pale Yellow Trillium is found naturally only in moist ravines in a narrow zone along the Savannah River in Georgia, South Carolina, and North Carolina. Many populations were lost to the extensive damming of the Savannah River and the subsequent flooding of its tributaries.

White Agreeable Tiger Moth on a Viburnum leaf

A White Oak twig bearing very young leaves
The tender leaves are protected by a dense coating of hairs and just a blush of anthocyanin (on the smallest leaf on the upper right).
Winged Elm bark is characterized by narrow oblong plates that some wag likened to tongue depressors.

Trailing (or Decumbent) Trillium occurs almost exclusively in Georgia’s northwest “limestone counties” but seems to thrive in the Lower Shade and Dunson Native Flora Gardens. Its stems are very short and curved (below), but don’t actually “trail” along the ground.

New Rambler Luna (left) and Nathan (right) looking for insects and fungi under a log. They turned up a beautiful, pinkish, resupinate polypore crust fungus (below).

The base of the slope just before the White Trail emerges onto the right-of-way is a reliable place to find lots of Rue Anemone, a wildflower that thrives at the Garden; deer avoid its toxic leaves and stems. It starts blooming in early March and continues well into May, pushing the envelope on the definition of a spring ephemeral. But its seeds bear elaiosomes, so we’ll let it stay in the club.

By late summer, Ramblers are pretty tired of the Garden’s weedy and ubiquitous Wingstems and Crownbeards, both in the genus Verbesina. But backlit in early spring, the wings are a nice sight. As Dale would always point out to Verbesina detractors, these plants are the host for lovely little Silvery Checkerspot butterflies.

Four-winged Silverbell trees at the edge of the floodplain forest are in flower.

The largest and densest witch’s broom we’ve ever seen

In the same area as the Silverbell, several Hop Hornbeam trees bear large, dense clusters of twigs and leaves in their canopies that are called “witches’ brooms.” Elizabeth Little, the Nature Ramblers' unofficial official plant pathologist, says: “a witch's broom is a plant growth abnormality characterized by a proliferation of shoots with very short internodes that result in a dense bundle of twigs. The cause varies with the type of plant. In the case of Hop Hornbeam, Hackberry, and Birch, the interactions of fungal pathogens such as a Powdery Mildew fungus and insects such as eriophyid mites damage terminal buds. The damage results in a malfunction of the plant's defense mechanisms leading to growth hormone imbalances and uncontrolled growth.”

Ground Ivy, the third member of Don's Three Amigos
Considering they are all in the Mint Family, perhaps we should call them the Three Primas. The other members of this trio are Purple Deadnettle and Henbit, below.



Ramblers searching for frog eggs in the ephemeral pools along the ADA path to the river
The pools immediately adjacent to the old unpaved path were lost to the installation of the ADA trail. There are pools further into the vegetation thickets but we found they are inaccessible without knee boots. Spring Peepers, Chorus Frogs, and American Toads have all been calling from here this spring.

The different world of the flooded slough between the base of the slope and the Middle Oconee River levee

Box Elder is a common floodplain tree with compound leaves
Bill spotted a Box Elder gall formed by a tiny midge that lays its eggs on the leaves, leaf buds, and leaf stalks of Box Elders. A gall forms around the egg and provides food for the larva after it hatches from the egg.

Wildflowers in the Middle Oconee River floodplain

Wild Chervil in flower beside the White Trail along the river

A weedy native found along the river bank, Kidney-leaf Buttercup has the extra-shiny yellow petals typical of buttercups.
Buttercups get their color from yellow pigments like many flowers do. But only recently have researchers discovered the reason why buttercup flowers are so much glossier than other flowers: “Buttercup’s exceptionally bright appearance is a result of a special feature of the petal structure. The epidermal layer of cells has not one but two extremely flat surfaces from which light is reflected. One is the top of the cells, the other exists because the epidermis is separated from the lower layers of the petal by an air gap. Reflection of light by the smooth surface of the cells and by the air layer effectively doubles the gloss of the petal, explaining why buttercups are so much better at reflecting light under your chin than any other flower.”

Wood Nettle is a species of stinging nettle that is abundant in the floodplain.
Wood Nettle’s stems and leaves are usually covered with stinging hairs (they may be shed by the end of summer). The glassy-looking hairs (below) are very brittle and, when brushed, break open and release a stinging compound that can irritate skin for hours or even days. Sufferers can console themselves with the fact that nettles are larval hosts for Red Admiral, Eastern Comma, and Question Mark butterflies.

Several spring wildflowers have tiny white flowers in small clusters. Beaked Corn Salad is distinguished by the strongly forked (dichotomous) branching of its stems and by its opposite leaves. It occurs in moist, frequently disturbed habitats such as floodplains.

Near the base of the ridge along the spur trail, we saw Butterweed in the greatest numbers of any place we’d seen them this morning.
Butterweed is an impressive plant  — often forming large populations  — with stout, ribbed stems and large, showy flower clusters composed of many flower heads. Even the foliage is impressive, each leaf divided into many differently shaped segments. Butterweed showed up in the Middle Oconee River floodplain after the dense thickets of Chinese Privet were removed. It is toxic to mammals (including deer and humans). Butterweed is a winter annual whose seeds germinate in the fall and form a leafy rosette that overwinters and then sends up a single flowering stem in the spring.

Ramblers spotted a vigorously flowering Cross-vine in a trailside tree. Cross-vine climbs by wrapping tendrils around a supportive tree or fence.

Cross-vine is one of the showiest of native vines, but the flowers are usually at the top of the tree that the vine used as a scaffold to reach the sun. Though it’s now commonly grown on the fences of native plant gardeners, it was a treat to get such a close look at these flowers in the wild. The flowers are pollinated by hummingbirds and butterflies.
A closer look at the stamens, style, and stigma of the Cross-vine flower. There are four stamens, each tipped with a small, oblong, pollen-producing anther, and a single style tipped with a sticky stigma.


Early Forget-Me-Not is covered with long, bristly hairs throughout.

Annual Fleabane in early flower

Ramblers welcomed new member Luna, whose stated objective for her first Ramble was to see a Carolina Anole. In the Forest Play Area, she not only saw a Carolina Anole but was able to catch (and release) one, as well.

At several locations during the Ramble, ramblers using the Merlin app identified Northern Parula songs. Though none of these birds were photographed, Don supplied a photo of a Northern Parula that he took in the Okefenokee Swamp with Mal Hodges during one of their lichen forays.

SUMMARY OF OBSERVED SPECIES
Oriental (Asian) False Hawksbeard         Youngia japonica
Eastern Red Columbine     Aquilegia canadensis
Piedmont Azalea     Rhododendron canescens
Pale Yellow Trillium     Trillium discolor
Viburnum     Viburnum sp.
Agreeable Tiger Moth     Spilosoma congrua
White Oak     Quercus alba
Winged Elm     Ulmus alata
Solomon’s Seal     Polygonum biflorum
Cranefly Orchid     Tipularia discolor
Chattahoochee Trillium     Trillium decipiens
Trailing (Decumbent) Trillium     Trillium decumbens
Resupinate Polypore Crust Fungus     Physisporinus crocatus (Tentative ID)
Jack-in-the-Pulpit     Arisaema triphyllum
Hearts-a-bustin', Strawberry Bush     Euonymus americanus
Rue Anemone/Windflower     Thalictrum thalictroides
Yellow Crownbeard     Verbesina occidentalis
Four-winged (Mountain) Silverbell     Halesia tetraptera
Hop Hornbeam     Ostrya virginiana
Ground Ivy     Glechoma hederacea
Henbit     Lamium amplexicaule
Purple Deadnettle     Lamium purpureum
Box Elder     Acer negundo
Box Elder gall midge    Contarinia negundinis
Wild Chervil     Chaerophyllum procumbens
Kidney-leaf Buttercup     Ranunculus abortivus
Stinging Nettle     Laportea canadensis
Beaked Corn Salad     Valerianella radiata
Butterweed     Packera glabella
Cross-vine     Bignonia capreolata
Early Forget-Me-Not     Myosotis verna
Annual Fleabane     Erigeron annuus
Mayapple     Podophyllum peltatum
Carolina Anole     Anolis carolinensis
Blue Japanese Oak     Quercus glauca
Coral Honeysuckle     Lonicera sempervirens
Northern Parula     Setophaga americana