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.”
OBSERVATIONS:
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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. |
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| Piedmont Azalea is planted at the
top of the paved path through the Lower Shade Garden. |
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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.
|
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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. |
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| White Agreeable Tiger Moth on a
Viburnum leaf |
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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).
|
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| Winged Elm bark is characterized
by narrow oblong plates that some wag likened to tongue depressors. |
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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.
|
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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).
|
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| 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. |
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| 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. |
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| Four-winged Silverbell trees at
the edge of the floodplain forest are in flower. |
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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.”
|
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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. |
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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. |
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| The different world of the
flooded slough between the base of the slope and the Middle Oconee River levee |
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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
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| Wild Chervil in flower beside the
White Trail along the river |
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A weedy native found along the
river bank, Kidney-leaf Buttercup has the extra-shiny yellow petals typical of
buttercups.
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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.”
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| 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.
|
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| 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. |
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| 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. |
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| 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. |
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| Ramblers spotted a vigorously
flowering Cross-vine in a trailside tree. Cross-vine climbs by wrapping
tendrils around a supportive tree or fence. |
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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.
|
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| Early Forget-Me-Not is covered
with long, bristly hairs throughout. |
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| Annual Fleabane in early flower |
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| 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. |
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| 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
