Leader for today’s
Ramble:
Linda

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.

Fungi and lichen identifications:
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.

Number
of Ramblers today: 31

Today’s emphasis:  Wildflowers, ferns, and shrubs on the Orange Trail

Perfoliate Bellwort

Today’s reading: Cathy Payne read a poem by M.K.
Creel, “In the Church of a Weeping Cherry”

After a storm, the miracle

of pale pink flowers,



tissue-paper lanterns

glimmering with honey



light. We seek shelter

in this humming



cathedral, held together

by cascading branches



and hundreds of

cellophane wings



glinting. The gloss

of promise overwhelms,



even in Winter’s false

spring – a feast for bees



already heavy

with pollen baskets.



A chipping sparrow

makes a thrilling entrance,



tilts its copper crown;

together, we listen.

Show and Tell:

Richard introduced a new method for controlling Eastern Carpenter Bees around our
houses: a fake hornet’s nest. Basically, it’s a brown paper bag stuffed with
plastic bags and other soft materials and shaped to resemble the large, papery
nest of a Bald-faced Hornet. Apparently, these bags fool Eastern Carpenter Bees
and make them leave the area – it’s not 100% effective but enough to make a dent in
the numbers of carpenter bees without resorting to a tennis racket. Here’s a video.

Bobbie brought a Luna Moth cocoon she found on the ground in her yard beneath a Sweet Gum tree. Luna Moths use Sweet Gum as well as Tulip, Black Walnut, Hickory, and Persimmon trees as larval hosts.

Roger displaying a bluestone sample

Roger brought his recent
collection of diabase rocks and their common look-alikes. Here’s his
presentation:

“Back in February we
took a winter hike at Camp Kiwanis north of Danielsville and walked along
Bluestone Creek. Later, I did some research and found that the creek got its
name from a rock called “bluestone.” I am not a geologist or a soil scientist,
but I’m trying to learn enough about rocks and soil to know how they shape the
natural environment around us. If you don’t know Bluestone Creek, you probably
do know about Stonehenge. The pillars of the inner circle at Stonehenge are
bluestone. Each of these pillars weighs over 4 tons; 4,000 years ago, people
hauled these pillars of bluestone 150 miles from their source to Stonehenge.

Geologists call bluestone
“diabase,” a form of lava or magma that is squeezed up into a vertical crack in
the earth’s crust. As the magma cools, it forms a wall in the rock known as a
dike. This dike may be only a few feet wide, but it can extend for several
miles in length. If you could dig it up, it would look like a blue wall across
the landscape. The diabase dikes in the Georgia Piedmont are about 200 million
years old. They were formed when the supercontinent Pangaea was breaking apart.
As the crust of Pangaea pulled apart, vertical cracks appeared. Magma flowed up
through these cracks and cooled to form diabase.

There are diabase dikes
here in Clarke County, one that runs along Timothy Road and another out on Belmont
Road, but they are deeply buried under the Piedmont soil. The only places you
can see diabase is along highway construction sites or railroad beds – or when
a line of bluestone crosses a creek. And this is what makes Bluestone Creek
special. Not only does the diabase dike cross the creek, this band of bluestone
runs down the middle of the streambed for a full quarter mile. I’m sure
the early settlers found this dark, blue-gray rock striking.

While diabase
is fascinating to me, it is also a stepping stone to learning about other
rocks. Here is a sample of granite from near my home in Oglethorpe County.
Granite and diabase are both igneous rocks, but diabase is a mafic rock that
weathers to form soil with a circumneutral or basic pH. Granite is a felsic
rock – the soil that develops from granite is more acidic and less fertile.

Next is a sample of biotite which at a glance looks a lot
like diabase because of its salt-and-pepper appearance, but biotite is a
metamorphic rock. In fact, biotite is a type of mica, and appears black because
of the iron and magnesium in its chemistry. One of the main rocks under the
Botanical Garden is biotite gneiss. The fourth rock is a chunk of amphibolite,
often similar in appearance to diabase. They are both mafic rocks, but
amphibolite is a metamorphic rock, that is, it’s an igneous rock that
was transformed by extreme heat and pressure into a different kind of rock.” (“Mafic”
is a word formed from magnesium and iron (Fe). “Felsic” rock is
rich in minerals that form feldspar and quartz.)

Announcements and other
interesting things to note:

Bob
Ambrose announced that his latest book of poetry “Between Birdsong and Boulder,
Poems on the Life of Gaia” has officially been published and is available for on-line
ordering at several sources. When hard
copies come in, he has arranged for a consignment to be sold at Avid.

Cathy Payne reminded us that she will
bring name tags and markers for us to make name tags. If you already have
one, please wear it. Lots of new ramblers this year means lots of new names!

Gary announced that the next Audubon meeting will be held at the Hargrett Rare
Book Library on Thursday, April 4, 7:00 p.m. at 300 S. Hull Street on north
campus. Jim Porter will lead a tour of his exhibit “Sunken Treasure: The Art
& Science of Coral Reefs.”


Today’s Route:  We left the
Children’s Garden, crossed the entrance road, and headed up the steps through
the Upper Shade Garden. After crossing the parking lot, we walked along the
Orange Trail, following the creek, then crossing over the stream at the new Hi-Water
Bridge. We returned on the Purple Trail, which we followed back up to the
International Garden.

Woolly Ragwort, a native species planted in the Children’s Garden, naturally occurs on many of the Piedmont granite outcrops near Atlanta but not at Clarke County’s Rock and Shoals outcrop (which is fine, there are other ragworts there).

Spring Snowflake, a European native, is planted near the Children’s Garden arbor.

The sidewalk alongside the Children’s Garden is lined with Southern Magnolia trees whose leaves are colonized by an alga that causes leaf spots and twig cankers. The colonies start out green then turn light brown and velvety when they produce spores; they may be up to 1/2 inch wide. Interestingly, the alga is often colonized by a fungus in the genus Strigula. The lichenized spots are light gray in color and are embedded with the black spore structures of the fungus. The alga is common in the hot, humid climate of the deep south and more often found on older leaves. Elizabeth, a rambler who is a plant pathologist, says that the algal spots are superficial, do not damage the tree’s health, and do not warrant pesticide spraying. Older leaves are routinely shed and should be raked up and removed to cut down on new infections. The alga is ubiquitous and may also infect other plants such as camellias and blackberries.

Yoshino Cherry, one of several ornamental cherry trees whose flowers inspire the Cherry Blossom Festival in Washington D.C. Cherries (genus Prunus) are in the Rose Family and have flowers typical of that family: five petals surrounding a cluster of numerous stamens.

Don’s photographer eye was caught
by these slug grazing tracks on a lichen growing on the bark of a Beech tree
along the walkway through the Upper Shade Garden (on the slope between the parking lot
and the Visitor Center).

Slugs have a tongue-like structure called a radula in their mouths that are covered with very many, very sharp, microscopic teeth. Here are some photos.

Woodland Phlox and Golden Ragwort planted along the steps to the parking lot.

Juneberry, planted in the Upper Shade Garden and widespread in the woods at the Garden, is the earliest of our native blueberries to flower. It produces fruit earlier in the summer than other species, as the name suggests. In this photo you can see slits cut in the base of the flowers by large bees eager to access the nectar within. Blueberry flowers have small openings at the tip of their flowers that admit small bees such as the SoutheasternBlueberry Bee (Habropoda laboriosa) but exclude larger insects such as Bumblebees and Carpenter Bees. Blueberry flowers are pollinated only by bees capable of “buzz pollination” such as the SE Blueberry Bee.

The winter woods at the Garden are characterized by the visually dominant layer of pale, papery leaves that persist on the branches of Beech trees.

In a process called marcescence, Beech, Hop
Hornbeam, and some oak species hold onto their leaves through the winter,
finally dropping them in the spring. We know how the first part of this process
works – a layer of weak cells (called the abscission layer) that forms at the
base of the leaf stalk on most other deciduous trees in the fall does not develop in these
species. But what about the last stage of this process? What triggers the trees
to finally let go of their leaves in the spring? Are the leaves torn off by wind
and rain? Or is it an active process triggered by the same cues that lead trees
to break dormancy and activate their buds in the spring?

Beech leaves are suddenly accumulating everywhere on the ground at the Garden.

Once on the Orange Trail, we began to see wildflowers
in their native habitats.

Wild Geranium

Three-parted Yellow Violet

Pennsylvania Bittercress

Kidney-leaf Buttercup

Wood Rush is an inconspicuous grasslike plant, but a close look (below) reveals that its small heads are full of delicately shaped and colored parts.

Rue-anemone

One of the questions I am most frequently asked during wildflower walks is: “what are these leaves,” with the questioner standing over a patch of leaves displaying every possible variation on the theme of hearts and arrowheads and animal feet. Shown above are the leaves of one of the Rattlesnake-root species, in the genus Nabalus, probably Tall Rattlesnake-root. During the ramble, I called this Lion’s-foot, which it may be – but we have to wait for its flowering to be sure. In midsummer, older plants will produce an erect stem about 3 feet tall, crowned by a cluster of small, drooping flower heads (yes, it’s in the Aster family).

The Orange Trail is famous (at
least among ramblers) for its fern diversity.

Christmas Fern “fiddlehead” This type of uncoiling by ferns is called “circinate vernation” and is the most common type of fern frond formation.

Broad Beech Fern unfurling its fronds

Rattlesnake Fern is unfurling its two types of fronds: a larger sterile frond (above) that does the heavy photosynthesis lifting for the plant, and small frond (below) that produces spores.

Southern Grape Fern

Rusty Blackhaw is a tall shrub or small tree of dry to moist woodlands, often over mafic rock. It’s not common in the Garden’s woods and I’ve never seen it flowering here. When it does, it produces lovely flat-topped clusters of small white flowers, like all of our native Viburnum species.

Rust-colored hairs cover the lower leaf surfaces, leaf stalks, buds, and new twig growth of Rusty Blackhaw.

Here’s a photo of Rusty Blackhaw in flower, taken by Gary this week in Oconee County

Painted Buckeyes are in bud. Their leaves are the first of our native woody plants to emerge. The leaves come with two lines of defense against late winter conditions: anthocyanin and pubescence. When their leaves first unfurl from the buds, they are colored dark red with anthocyanin, a plant pigment that protects new cells’ fragile machinery from ultraviolet light falling through the still leafless canopy. Enlarge Don’s photo of expanding leaves to see how their leaflets and stalks are covered with a dense coating of tiny white hairs (pubescence) that reflects light during the day and, at night, holds heat that may have built up on the leaflet surface during the day. The pubescence is shed as the leaves mature, ultimately leaving the leaves smooth and hairless.

SUMMARY OF OBSERVED SPECIES:

Spring Snowflake        Leucojum vernum
Woolly Ragwort     Packera dubia, synonyms: Packera
tomentosa, Senecio tomentosa

Algal leaf spot on Southern Magnolia leaves    Cephaleuros
virescens

Yoshino Cherry     Prunus X yedoensis

Juneberry, Elliott’s Blueberry     Vaccinium
elliottii

Daffodil (white)     Narcissus
papyraceus (tentative; scientific name for a/the white daffodil)

American Beech     Fagus
grandifolia

Golden Ragwort     Packera aurea

Woodland Phlox, Blue Phlox     Phlox
divaricata

Tufted Titmouse     Baeolophus bicolor

Common Blue Violet     Viola sororia

Rue Anemone     Thalictrum
thalictroides
May-apple     Podophyllum peltatum

Wild Geranium     Geranium maculatum

Wood Rush     Luzula echinata

Kidney-leaf Buttercup     Ranunculus
abortivus

Pennsylvania Bittercress     Cardamine
pensylvanica

Three-parted Yellow Violet     Viola
tripartita

Perfoliate Bellwort     Uvularia
perfoliata

Wild Chervil     Chaerophyllum
tainturieri
Tall Rattlesnake-Root 
 Nabalus altissimus, synonym:
Prenanthes altissima
Southern Grape Fern     Sceptridium
biternatum, synonym: Botrychium biternatum
Rattlesnake Fern     Botrypus
virginianum, synonym: Botrychium virginianum
Christmas Fern     Polystichum
acrostichoides
Broad Beech Fern     Phegopteris
hexagonoptera
Painted Buckeye     Aesculus sylvatica
Rusty Blackhaw     Viburnum rufidulum