This post was written by Don Hunter. I selected a few of his photographs from his Flickr sets to accompany his narrative; you can find them here.
Twenty Ramblers, including several very welcome new folks,
gathered at the Visitor Center parking lot on the afternoon of January 16 for a
Ramble on what turned out to be a beautiful and surprisingly comfortable
afternoon. Both the Sun and everyone’s
spirits
Cold? No — just a little chilly |
were high and bright as the group headed off from the parking lot for
today’s Ramble, organized by Don, Dale and Emily. The main areas of concentration today were
lichens, fungi and liverworts. We left
the parking lot and headed down the path towards the International Bridge, then
on to the Purple Trail. At the river, we
headed left on the Orange Trail and followed it around the Beaver Pond to the
foot bridge across the creek, where, after a short walk past the bridge, we
viewed liverworts in the stream and a budding Round Lobed Hepatica. We then returned to the bridge and headed up
the trail to the Flower Garden and on back to the Visitor Center. The following narrative is a detailed
description of the various interesting things viewed on the Ramble. Also included are several things not viewed on
the Ramble but were observed earlier on the same route in preparation for the
Ramble and are worth sharing.
After leaving the parking lot, we headed over to the
International Bridge for our first stop.
At the south end of the bridge we stopped at a large Florida Azalea (Rhododendron austrinum) with many heavily lichen encrusted limbs. Several species of lichen were observed,
including Old Man’s Beard, also known as Bushy Beard lichen, (Usnea strigosa),
Perforated Ruffle Lichen (Parmotrema perforatum) and Powdered Ruffle Lichen (Parmotrema hypotropum), as well as several
unidentified species.
After we all had a chance to see the lichens at the bridge,
we headed over to the large rock outcrop along the path and stopped to view the
lichen patches on the large American Beech trees (Fagus grandifolia), located right next to the outcrop, as well as
on the Northern Red Oak (Quercus rubra),
located directly across the path from the outcrop. The American Beeches, with their smooth
bark, are hosts to many of the crustose lichens, providing a large canvas on
which we can see veritable works of art, courtesy of Mother Nature. For most of these, we (the Rambler crew) don’t
have an identification, at this
Script Lichen |
time, but we were able to identify examples of
Common Script Lichen (Graphis scripta).
Also seen at this stop, were several examples
of slug grazing tracks or trails.
Lichens are symbiotic organisms, comprised of a fungal component (the
mycobiont) and an algal component (the photobiont). The algal component (either green algae or
cyanobacteria (formerly called bluegreen algae)) is typically found under the
cortex or “skin” of the
Marks made by grazing slug feeding on lichen |
lichen, and within the medulla, intermingled with a
loose network of fungal hyphae or filaments.
The slugs graze on the lichen, feeding on both the fungal tissues and algal cells. As the slugs graze, a curved, chitinous
organ, called a radula, extends from the mouth.
The radula is covered with denticles, essentially teeth, which point back
towards the mouth. As the radula is
retracted, the denticles scrape through the upper cortex of the lichen and remove
the algae and hyphae from the substrate and deliver it into the mouth, where it
is deposited in the esophagus. This
grazing leaves a very distinctive, though sometimes difficult to see,
pattern. The patterns are most visible
when the bark is wet and the radula scrapes completely through the lichen into
the substrate, providing contrast.
The Northern Red Oak seen across the path, though not
smooth-barked like the American Beeches, does have broad and smooth bark
plates, separated by furrows, which provide sufficient surface area for obvious
crustose lichen development. Some very
nice, small and densely “scripted” script lichens, as well as other species,
were observed on this tree. We are not
sure, at this time, if this is the Common Script lichen or another species.
Numerous lichens are also visible on the large rock outcrop
and the smaller exposed rock seen around it.
These were not identified but did make for nice viewing. Perhaps we can concentrate on these lichens
on a future Ramble.
After viewing the lichens at the outcrop and on the Northern
Red Oak, we turned right onto the Purple Trail.
Immediately on the left is another large American Beech, with heavy
encrustation of lichens. We passed this
tree and next came upon an Eastern Hophornbeam (Ostrya virginiana). Visible
on this tree, and just about every other Ostrya
Hornbeam Disk Mushroom |
on the trail, were numerous small, curled-edged mushrooms, the Hornbeam Disc
mushroom (Aleuodiscus oakseii). A week ago, these mushrooms looked
completely different, being much larger, with little, if any, of the curling
and shrinkage visible today, despite the enormous amounts of rain we’ve had in
the past week.
A little further down the trail, Bob pointed out a moss
growing on what appeared to be a disturbed mound of earth on the trail. The tentative identification of this moss is
either Slender Starburst Moss (Atrichum
angustatum), most likely, or perhaps Beaked Comb moss
Moss with sporophytes |
(Rhynchostegium serrulatum).
A sporophyte was removed and described for everyone, revealing a
slender, erect stalk, with a relatively long capsule with hood. Hugh calls this the “Sausage Moss” because of
the large and distinctive capsule topping the stalk.
At our next stop, we ventured off-trail to make a few
observations at a large American Holly tree (Ilex opaca). Not only was it, with it’s smooth bark, a
suitable host for the crustose lichens, it also presents some very interesting
scars where limbs have been lost during growth.
This particular tree was near the upper range of 40 ft. to 50 ft. in
height these trees can achieve. As a result,
there were numerous limb scars on the lower reaches of the trunk, all looking
amazingly like human eyes staring back at you.
Many of these scars were encrusted with patches of script lichen,
appearing almost as gray, speckled lava flows emanating from the tops of cinder
cone volcanoes (the eyes). An American
Hop Hornbeam was located nearby, with
many Hornbeam Disc mushrooms, as seen previously on other of the same species.
Several examples of a creamy white slime mold, possible
Tapioca Slime Mold (Brefeldia maxima),
were seen on roots, and even rocks, along the trail. These same examples were seen in the past
week and were much fresher, looking like shiny cottage cheese. Today they were of diminished size and had
many cracks, evidence that they have begun to dry out.
Brown Tooth Crust Fungus |
Further on down the trail we made another stop, this time to
look at a Horse Sugar shrub,
Horse Sugar |
also known as Sweet Leaf (Symplocos tinctoria). Also
seen here was a fallen limb that was passed around, displaying several lichens,
as well as Brown Toothed Crust fungus (Hydnochaete
olivaceum), which can often be found as a crust on the bottoms of limbs
that have fallen to the ground. Nearby,
Hugh had taken a group off-trail into the woods to admire a very large American
Persimmon tree (Diospyros virginiana),
which towered high into the canopy. This
is one of the largest, if not the largest, American Persimmon tree on the
property of the garden.
Before the last bend in the Purple Trail, we stopped at a
large American Beech so that everyone could see the Black Sooty mold (Scorias spongiosa) on several lower
limbs. The
Sooty Mold fungus on Beech |
mold avails itself of the
sugary excreta from large numbers of Beech Blight aphids, found during the
warmer months infesting Beech trees at numerous locations throughout the wooded
areas of the Garden.
Near the end of the Purple Trail there was plenty to see. The area between the Purple Trail and the
Beaver Pond was littered with fallen limbs, most all of which provided nice
lichen viewing. On one of the limbs, we
observed many small patches of a purple fungus called Silver leaf fungus (Chondrostereum purpureum). Many times Ramblers ask, when
Silver leaf fungus (in purple) |
observing dense
or heavy growths of mushrooms or lichens or large infestations of Beech Blight
aphids, if the tree is adversely affected by such a presence. Normally, any effect is localized to a limb
and the entire tree’s health is not impacted.
This is one case where there may be health implications related to the
presence of this organism. To learn more about Silver leaf fungus click on this
link to the Wikipedia
article.
At this same location approximately one week ago, a dead
limb was observed with an orange fungus or lichen, upon which several slugs
were seen grazing. The typical grazing
pattern could be seen along one edge.
But today, the day of the Ramble, the orange mushroom or lichen was not
visible, being completely removed by the slugs, leaving only a faint scar where
the organism was attached. Amazing. Before leaving the area to head to the Orange
Trail, a small Chalk Maple (Acer
leucoderme) was pointed out on the side of the trail, still bearing most of
its golden brown and papery leaves.
We turned left onto the Orange Trail and made our way down
the river and turned left near the turn-off to the Heath Bluff trail to skirt
around the east side of the Beaver Pond.
Numerous American Hornbeam or Musclewood trees (Carpinus caroliniana), with their sinewy bark and patches of Fan
Moss (Forrstroemia trichomitria), and
River Birches (Betula nigra), with
their exfoliating bark, in curly papery sheets, were seen as we moved along the
banks of the Middle Oconee River.
At the bridge where the trail passes over the outfall stream
from the Beaver Pond, Hugh relayed an interesting observation. During the flooding that occurred last week,
the river rose so high that it came within four inches of the handrails on the bridge,
as evidenced by the high water mark on the support post for the handrails.
Not far away, as we made the turn at the Heath Bluff Trail,
we found a large, dead limb on the ground, nearly covered with lichens. We observed lichens already seen on the
Old Man’s Beard; Perforated Ruffle Lichen |
Ramble (Old Man’s Beard, Perforated Ruffle lichen, and Powdered Ruffle lichen)
and also saw a nice example of a rim lichen (Lecanora sp.) on the limb.
Nearby, someone also pointed out a Christmas Fern (Polystichum acrostichoides).
Further up the trail, another large fallen limb, with a
smorgasbord of lichens was viewed. The observed lichens included most of the
usual suspects seen up to this point but also a good example of the Common
Greehshield lichen (Flavoparmelia
caperata).
As we moved along the Orange Trail, we stopped at numerous Carpinus and observed patches of liverwort
(Frullania sp.) and Fan Moss on the
trunks of the trees. (The
Liverwort on Beech |
liverworts
were present, to some extent, on American Beeches as we made our way down the
Purple Trail at the beginning of the Ramble, but became more common and
frequent on the Carpinus along the
river and up, the Orange Trail. Later,
towards the end of the Ramble, we also saw nice liverwort on the American Beech
trees as we approached the Flower Garden.)
As we left the Beaver Pond behind and encountered the creek,
we stopped to observe the
Dragonfly nymph |
many snail trails in the sediment coating the bottom
of the creek. Joan fished one of the
snails out to view, as well as a dragon fly nymph (neither identified).
Round Lobed Hepatica |
Next came the highlight of the day, as we arrived at the
foot bridge crossing the creek. Here, blooming
since January 2, we saw a beautiful lilac-colored Round Lobed Hepatica (Anemone americana), the first wildflower
to bloom, not only at the Botanical Garden, but at most places from Athens to
the north.
Flower of Round Lobe Hepatica |
Moving up along the trail we saw several nice examples of
Smokey-eye Boulder lichen (Porpidia
albocaeralescens) with its characteristic smoky, gray spots and several Spotted
Wintergreen, aka Pipsissewa (Chimaphla
maculata) growing on the banks of the trail.
Smoky-eye Boulder lichen |
We briefly detoured upstream from the bridge to view another
Round Lobed Hepatic that was about to bloom.
Along the way, we saw several fairly large patches of green liverwort,
possibly Scented liverwort (Conocephalum
conicum) growing on rocks in the stream.
Two cotyledons of an acorn; root at bottom; shoot not yet developed. |
After most of the group had moved to the bridge to begin the
climb up the trail to the Flower Garden, Dale described, to a very small
audience (Don, Joan and Sandra), how oaks grow from acorns. The “meat” of the acorn is really
the two seed leaves — called the cotyledons.
They store the carbohydrates and oils that provide the energy for the
baby oak. The first part to emerge from the acorn is the embryonic root which
grows downward into the soil. After growing to a length of 6 to 12 inches the
embryonic shoot takes off, growing upwards. The growth of the shoot is
dependent on the root for water and minerals and the cotyledons for the energy
it needs to elongate and produce leaves.
Tree bark fungus (light patch on left) |
At this point, we turned around to cross the bridge and head
back to the Visitor Center. Near the end
of the trail, Dale pointed out, on several trees, evidence of a fungal disease,
presented as large patches of bark that was lighter in color, nearly white in
some examples, and noticeably thinner than the surrounding unaffected bark. This is caused by a fungus similar to the
Hornbeam Disc mushroom.
Back at the Visitor Center, several of us retired to
Dondero’s for refreshments and conversation.
Everyone agreed that it had been a really nice Ramble, with great
weather (as it turned out!) and many neat observations.
Species observed on today’s Ramble:
Florida
Azalea (Rhododendron austrinum)
Old Man’s
Beard AKA Bushy Beard lichen (Usnea
strigosa)
Perforated Ruffle
Lichen (Parmotrema perforatum)
Powdered
Ruffle Lichen (Parmotrema hypotropum)
American
Beech trees (Fagus grandifolia)
Northern Red
Oak (Quercus rubra)
Common Script
Lichen (Graphis scripta)
American Hop
Hornbeam (Ostrya virginiana)
Hornbeam
Disc mushroom (Aleuodiscus oakseii)
Slender
Starburst Moss (Atrichum angustatum)
American
Holly tree (Ilex opaca)
Tapioca Slime
Mold (Brefeldia maxima)
Horse Sugar shrub
(Symplocos tinctoria)
Brown
Toothed Crust fungus (Hydnochaete
olivaceum)
Black Sooty mold (Scorias
spongiosa)
American
Persimmon tree (Diospyros virginiana)
Silver Leaf
fungus (Chondrostereum purpureum)
Chalk Maple
(Acer leucoderme)
American
Hornbeam or Musclewood (Carpinus
caroliniana)
Fan Moss (Forrstroemia
trichomitria)
River
Birches (Betula nigra)
Rim lichen (Lecanora sp.)
Christmas
Fern (Polystichum acrostichoides)
Common
Greehshield lichen (Flavoparmelia
caperata)
Liverwort (Frulannia sp.)
Round Lobed
Hepatica (Anemone americana)
Smokey-eye
Boulder lichen (Porpidia albocaeralescens)
Spotted
(Wintergreen) Pipsissewa (Chimaphla maculata)
Scented
liverwort (Conocephalum conicum)