Ramble
Report October 27, 2022
Leaders
for today’s Ramble: Jean Lodge and Bill Sheehan
Authors
of today’s Ramble report: Jean Lodge and Bill Sheehan. Comments, edits, and suggestions
for the report can be sent to Linda at Lchafin@uga.edu.
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 your mouse or tapping your screen.
Number
of Ramblers today: 27
Today’s
emphasis: Fungi
Today’s
Route: From
the Children’s Garden arbor, we headed down through the “Chestnut Tree” to the
White Trail, which we followed down the hill to the Middle Oconee River
floodplain. We returned via the same
route.
Show and Tell:
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| Maple Tarspot on a Striped Maple leaf |
Jean brought
in a specimen of Maple
Tarspot, one of two parasitic Tarspot fungi that cause lesions on Maple leaves.
She found this one on a Striped Maple (Acer
pensylvanicum) leaf in the Georgia mountains. We looked for it on maples at
the Botanical Garden but didn’t find it. Other species of Tarspot infect Rhododedron or other hosts. The black
structures (sporangia) are often boat-shaped and have a slit-like opening for
releasing their spores (click or tap on your screen to zoom in).For additional information on Maple Tarspot and related species, see here and here.
 |
| Pilobolus sporulating bodies on deer dung. Below, container lid peppered with sticky spores. |
Bill brought a dish with deer dung collected the previous week at the Botanical Garden. The dung had
sprouted hundreds of stalks of the fungus Pilobolus.
The genus name means “hat-thrower” and it is very descriptive. The black dots are
spore clusters called sporangia that sit on clear, fluid-filled sacs (left)
that rupture and propel the sporangia up to 10 feet away. The acceleration of the
sporangia is reportedly one of the fastest organic bodies in nature: launching
with an acceleration of 20,000 G’s, twice that of a rifle bullet. When the
sporangia land on grass, they stick to it and then may be eaten by herbivores,
like the deer that ate the spores that produced these fungi. (The spores really
stick. The sporangia on the lid in the lower photo were difficult to scratch off even
with a fingernail!) The spores pass
through the herbivore’s gut and begin the cycle again.
Gary brought in a section of a Chinese Wisteria vine and explained: “The
age of most woody plants can be determined by counting the annual growth rings
in a cross-section of the trunk. Determining the age of a Chinese Wisteria
vine, however, is exceedingly difficult because its annual growth rings are
indistinct and nearly impossible to see. A count of what appear to be growth
rings seen in this vine’s cross-section would indicate that this large vine is
about 10 years-old. But this vine is probably 70 to 80 years-old! In Wisteria, these mysterious dark rings
occur periodically at intervals of five to 10 or more years. Wisteria
vines typically twist together, forming a rope-like cluster of two or more
individual vines. As these vines grow and
expand, they fuse together, encircling a portion of the intersecting outer bark
within the new wood. These dark rings are believed to be deposits of bark
material that become enclosed during growth spurts.”
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| Sycamore leaves make excellent Halloween masks! |
Announcements: November
9, 6:30 – 8:00p.m. The Johnstone Lecture, sponsored by the
Friends of the State Botanical Garden of Georgia, was named in honor of the
Botanical Garden’s first director, Dr. Francis E. Johnstone, Jr., and
highlights an environmental topic. This year we are proud to announce that
Cassandra Quave, author of “Plant Hunter,” will join us. The lecture will be held in the Visitor Center at the Botanical Garden. The lecture
will begin at 6:30 p.m., with a reception and book signing at 7:30 p.m.
This event is free and open to the public, but reregistration is required here.
Fungi
The
key thing about fungi is that the vast majority of their bodies is composed of usually invisible filaments (hyphae) that make up the mycelium, or vegetative body, of a fungus. Hyphae are usually hidden in a substrate such as soil,
wood, leaf litter, or parts of a plant. What we usually think of as “fungi” or “mushrooms” are the easily seen reproductive structures that produce spores. Most photos in this report are of the spore-producing bodies of fungi that feed on living wood or
leaves (parasitic) or dead wood or leaves (saprotrophic). If the recent weather
had been wetter, we would have seen the large, fleshy mushrooms on the ground
that people typically associate with the word “fungi.” Many of the mushrooms we
would have seen are those that form beneficial symbioses, called mycorrhizae, with live plant roots.
 |
| Root-like structures, called rhizomorphs, of Honey Mushroom growing under the bark of a rotting tree trunk. |
Rhizomorphs,
mycelial cords, and hyphal strands are all root-like structures. We found the shoestring-like rhizomorphs of Honey Mushroom
under the bark of a log. Honey
Mushroom has a bioluminescent mycelium that makes logs glow under
favorable conditions and is referred to as foxfire.
Some species of Armillaria produce these
shoestring-like rhizomorphs which they use to find a new tree to decompose. Armillaria mellea is not a tree
pathogen, but A. gallica in Eastern
North America and A. ostoyeae in
Western North America are both tree pathogens that produce an expanding ring of tree death. The
tree-killing Armillaria use energy
obtained by decomposing dead trees to produce rhizomorphs at the bases of the
nearest susceptible trees around them and pump out toxins that kill the trees,
and are first on the doorstep to take over the dead trees and use them as new
food bases. Although these Armillaria
species are tree pathogens, they are not parasites because they don’t grow in
live trees, so they function like predators of trees. Both the Eastern and
Western tree pathogens can grow to very large sizes and have been referred to
as the “Humungous Fungus.”
Information
on Armillaria ostoyae tree
pathogen and the Humungous Fungus can be found here and here.
There
is also a ‘Humungous fungus in Michigan That Is as Massive as Three Blue Whales.
Rhizomorphs,
mycelial cords, and hyphae are all root-like structures produced by fungi to
connect between old and new food sources. Wood decomposing fungi (basidiomycetes)
use these structures to locate newly fallen or standing dead trees across large
distances. By sending out rhizomorphs, the original fungal colony can assess how large a new food source is and how much of it is
unoccupied by competitors. Based on the information they receive, they then
self-digest their own mycelium in the old food source and move to the more
profitable new food source. Once there, they expand their body size rapidly.
Fungi haven’t heard that you can’t take it with you when you die.
And just in time for Halloween….
 |
| Witches’ Butter, a jelly fungus |
(Remember to click or tap on a photo to zoom in)
Mushrooms
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| Deer Mushroom |
Deer
Mushroom grows on dead wood and is common year-round. Deer Mushroom has gills that are not attached to the top of the stalk.
The gills are white when young, like we found them (above), but appear
pinkish-brown when the spores mature. It is important to photograph both the
top and underside of mushrooms for identification, as above. An additional
critical step in identifying mushrooms is making a spore print, as shown below.
You simply place the cap face down on a piece of paper, glass or tinfoil, cover
with a bowl (below, left) to create a humid environment, and wait 2 to 24 hours, depending on
the age and type of specimen, for the spores to descend and form a print (below, right).
 |
| Photos by Bill Sheehan |
 |
|
Gymnopus sp.,
|
Some leaf decomposer fungi, such as this Gymnopus, bind leaves together in a mat.
The fungus does this to aggregate enough resources from a collection of leaves
to be able to fruit and produce spores. A benefit to the forest is that leaf
litter mats maintain litter and the underlying soil on steep slopes, preventing
erosion.
Bracket Fungi
 |
| Turkey Tail bracket fungus Striped top surface (left); white bottom surface with visible pores (right) |
Turkey
Tail and False Turkey Tail (below) bracket fungi are two of the most commonly observed
wood-rotting fungi in the woods around Athens. They persist on dead hardwood
long after they have released their spores because of their tough structure.
The banding on the top surfaces of both species is quite variable, so you have
to look underneath to identify them. Turkey Tail is white underneath with
visible round pores; False Turkey Tail is smooth underneath, with no visible
pores, and tan-colored. Turkey Tail is widely sold for its medicinal value.
 |
| Gilled Polypore Top surface (left), bottom surface with gills (right) |
It
is highly unusual for a polypore (“many pores”) fungus to have gills – but this
one does. This species was long placed in a different genus, Lenzites, until DNA studies proved that it is in fact closely related to Turkey Tail.
 |
| Gloeoporus dichrous (no common name) Top surface (left), bottom rubbery surface with pores (right) (Photos by Bill Sheehan) |
Michael Kuo maintains a marvelous website on fungi, www.mushroom.expert.com, that’s both technical
and humorous at times. Here’s what he says about this bracket fungus:
“This interesting little polypore [Gloeoporus dichrous] is a decomposer of
hardwood logs across the continent. Viewed from above, its creamy to white cap
is a bit boring – but its striking underside features an unexpected brown to
reddish-brown pore surface. In fact, the pore surface becomes even more
interesting if you have descended deep into the mire of myco-geekishness and
are willing to pry at it with a dissecting needle or tweezers: the tube layer
is rubbery in consistency, and is separable from the cap as a layer. Now that’s
entertainment.”
(Remember to click or tap on an image to zoom in)
 |
| Thin-walled Maze Polypore We saw these beauties during last week’s ramble as well. Despite appearances, the maze-like structures are not gills, but elongated pores. Top surface (left), bottom surface (right) |
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| Ganoderma [maybe] sessile |
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|
Little Nest
|
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| Cross-section of the Phellinus crust, showing pores |
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| Polypore fungus with irregular pores |
Crust Fungi
Crust fungi is a general term for the sporulating
basidiomycete fungi that lie mostly flat against dead wood (some may have a bit of a lip
protruding) and
usually lack pores. You’ve got to be a log-turner to be a crust nerd because they’re
usually found under dead logs on the ground or low on the sides of dead logs.
Some are wispy filaments, some are hard and tough, and some have bumps,
teeth, or wrinkles. Some are small discs while others may stretch the length of
a dead log.
 |
| A beautiful lemon-colored wispy crust, maybe Phlebia subochracea |
(Remember to click or tap on a photo to zoom in)
Ascomycete Fungi
We found several representatives of ascomycete fungi. This is a large and varied group of fungi that
tends to be small so are usually less frequently noticed than basidiomycetes, the other large group of fungi that includes
mushrooms, bracket fungi, crust fungi, jelly fungi, and more. The difference
between the two groups lies in how spores are produced and arranged.
 |
| Cramp Balls |
Each
little bump on the surface of Cramp Balls covers a tiny chamber that shoots
out spores. As is typical of ascomycetes, the spores are contained in a column-shaped
sac, usually eight to a sac. Annulohypoxylon,
the Cramp Ball genus, was separated from the genus Hypoxylon based on DNA evidence, but also differs from Hypoxylon by the flat rings surrounding
the ‘bumps’ (ostioles) from which the spores are released, and by the black
carbonaceous interior that does not produce bright pigments when potassium
hydroxide is applied. Zoom in on the upper left and far right fruiting bodies
to see the flat ring (annulus) around the openings. Compare to the orange flesh
of true Hypoxylon, below.
 |
| Hypoxylon sp., maybe H. rubiginosum or H. crocopeplum |
Cup Fungi
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| Purple Jellydisc, a wood-rotting fungus, grows mainly on the trunks and branches of dead Beech trees, where it often forms large, showy clusters. (Photo by Bill Sheehan) |
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|
Blue-stain fungus (Chlorociboria aeruginosa) is most often seen as a distinctive |
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| Orbilia sp. Some species in the family Orbiliaceae are carnivorous and trap and digest nematodes. |
For more info on nematode-eating fungi, see Else
Vellinga’s article on Oyster mushrooms and their relatives: “Fungal Snares and Other Sticky Ends,” here.
 |
|
Two unidentified
|
Slime
Molds Are Not Fungi
Once considered part of the fungi kingdom, slime molds don’t
fit comfortably into any of the five currently recognized kingdoms, but are
placed in the Protista kingdom, a sort of grab bag of primitive, single-celled
organisms. The visible slime molds we most often encounter are in the group,
Myxogastria. When food is abundant, these slime molds exist as single-celled
organisms, feeding on microorganisms that live in any type of dead plant
material. When food is in short supply, many of these single-celled organisms
come together and start streaming as a single body. They then form reproductive
bodies – sporocarps – like those seen below, often a tiny spore-containing ball
on a slender stalk. These are typically a millimeter or two high so are most
easily spotted when they aggregate. (The Dog Vomit Slime is an exception as it
can cover a foot or more on wood chips or other dead wood.) The ability of
slime molds in the streaming stage to solve problems, such as finding the
shortest path through a maze, has led to their being used to plan rail and
subway lines. Some researchers use the term “intelligence” to describe this
ability.
 |
| Wasp Nest Slime Mold |
This
slime mold has clusters of spherical capsules on short stalks. The spores are
borne on filaments within the capsules. Spores are dispersed when the head
bursts, leaving the filaments (red fluff in the photo). The empty bottoms of
the capsules look like the nests of paper wasps, hence the common name. The
scientific name, vesparium, also
refers to the family that paper wasps are in, Vespidae.
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| Jean Lodge sharing her extensive fungi expertise with Ramblers |
OBSERVED SPECIES:
Maple Tarspot Rhytisma acerinum
Hat-thrower fungi Pilobolus sp.
Chinese Wisteria Wisteria sinensis
Honey Mushroom Armillaria mellea
Witches’ Butter Tremella mesenterica
Deer Mushroom Pluteus cervinus
Leaf-rotting fungus, no common name Gymnopus sp.
Turkey Tail Trametes versicolor
False Turkey Tail Stereum ostrea
Gilled Polypore Trametes [Lenzites] betulinus
Wood-rotting polypore, no common name Gloeoporus dichrous
Thin-walled Maze Polypore Daedaleopsis confragosa
Polypore, no common name Ganoderma [maybe] sessile
Little Nest Polypore Poronidulus [Trametes] conchifer
Poroid crust, no common name Phellinus sp.
Polypore fungus with irregular pores unknown species
Crust fungus, no common name maybe Phlebia subochracea
Cramp Balls Annulohypoxylon sp.
No common name Hypoxylon, maybe H. rubiginosum or H. crocopeplum
Purple Jellydisc Ascocoryne sarcoides
Blue-stain fungus Chlorociboria aeruginosa
Cup fungus, no common name Orbilia sp.
Two species of cup fungi unknown species
Slime mold, no common name Physarum sp., likely stellatum
Wasp Nest Slime Mold Metatrichia vesparium
A Halloween Postscript: In Ghostly
Graveyards, Biodiversity Is Nourishing the Living
Postscript: the best trail map for the Botanical Garden I’ve seen.