Saturday, August 27, 2016

Ramble Report August 25 2016


Today's Ramble was lead by Linda Chafin.
Here's the link to Don's Facebook album for today's Ramble. (All the photos in this post are compliments of Don unless otherwise credited.)
Today's post was written by Dale Hoyt.

No. attending: 20

Today's reading:
Bob Ambrose treated us to another of his poems:
 
On The Necessity of Coronata

There is a final dignity to it all, 
a calling in the cogs and cycles,
the bones and blood of Gaia.

Consider the coronata, just 
a common perching bird, honed 
to grace the New World winter.

Perhaps you caught an idle glimpse 
looking out from the kitchen sink 
as the spring wave worked north.

You may call them butter butts. 
They are not diminished 
but go about their business 

skimming insects from the surface 
of rivers, gleaning from leaves, 
stealing from spiderwebs, 

warbling the northern woods in summer.
They flit through conifer stands
flashing butter yellow rump, 

then flood the continent in fall 
from the great blue-green spruce 
down ancestral flyways. 

In the dearth of winter they settle 
into Southern scrub, Eastern woods, 
and mountain hollows to digest the wax 

from myrtle berries. Someone must — 
it’s a niche, and who’s to say a minor 
role, this living piece of the whole?

(Note: If you're mystified by the title of Bob's poem maybe this will help: the scientific name of the Yellow-rumped Warbler is Setophaga coronata; it is also colloquially called "butter butt.")

Announcements:

Thurs., Sept. 1, 12:30PM; Sher & Barbara Ali invite Ramblers for a Pizza Luncheon at their TREEHOUSE at 170 Evergreen Terrace off of Cherokee Road in Winterville, GA. Children & Grandchildren are welcome. If you will attend let them know at 706-202-5324 or 706-247-1769.

Weds., Sept. 7, 9AM; @ Sandy Creek Nature Center. Guided Walk with Carmen Champagne looking for spiders, insects & other small creatures. Carmen has a great eye for spotting these little animals. Not only can she identify them, she knows lots about their natural history.

Weds., Sept. 14, 7-8:30PM; An Evening of Poetry and Nature @ Russell Special Collections Library. Free parking at Hull St. Deck next to the Library. An evening of local authors celebrating poetry and nature hosted by UGA Friends of the Georgia Museum of Natural History. Reading their poems will be: Philip Lee Williams, Clela Reed, Robert Ambrose, Jr. and retired Ecology professor John Pickering. For more information and directions click here.

Today's route: Down the White trail to the power line and then to the river.

Mystery fruit: Only a short way into today's ramble we found what at first looked like an Oak apple gall, but it was solid (the gall is hollow). Cutting it open revealed something that looked like a seed, but of what plant no one had a clue. Continuing downhill, we found what looked to be a cache of a half dozen or so of these fruits, possibly stashed by a squirrel. After the ramble and some googling Linda came to the conclusion that it was the fruit of one of the many Camellias in the Shade garden.

Chanterelle mushrooms
False Chanterelle mushrooms growing on wood.
Thanks to the recent rains Mushrooms have finally made an appearance in the Garden. On the White trail, going downhill toward the power line we found a few Chanterelles and a group of mushrooms growing on a decomposing log that we're calling False Chanterelles, but they don't match a lot of the descriptions seen on the internet. True Chanterelles grow from the soil, so the ones we found on the log are not true Chanterelles. True Chanterelles are roughly trumpet shaped and have gills that continue a short distance down the stalk from the cap. These are not true gills; they are simple folds, but, like true gills, they are the spore producing surfaces of the mushrooms.
Fragile Dapperling mushroom before losing its head. 
We also found a number of Fragile Dapperling mushrooms. These tall, delicate looking mushrooms resemble Japanese parasols. One of the Ramblers found the common name very appropriate when she gently touched the cap and it immediately fell off.

The nature of a mushroom: The hidden body of a mushroom is called the mycelium and is invisible to us. It consists of a vast network of microscopic threads, called hyphae (singular, hypha) that weave and tangle through the substrate (e.g., soil, dead leaves or logs) they grow in. The hyphae secrete enzymes that break down organic material much like our digestive tract breaks down our food into simpler molecules. These smaller molecules are then absorbed by the hyphae and used to make more of the fungal mycelium. Similarly, our small intestine absorbs the products of digestion.

Mushrooms call into question common ideas about sexual reproduction: Mushrooms are the fungal equivalent of flowers in the sense that the function of flowers is to produce seeds. Like flowers, a mushroom's function is sexual reproduction. They produce microscopic spores, the functional equivalent of seeds, that can be carried great distances by air currents. But with mushrooms the sexual part of reproduction occurred long before the mushroom appeared. It happened when genetically different hyphae met underground and fused with one another. This fusion produces hyphae that contain two distinct nuclei. As the hyphae continue to grow each kind of nucleus also divides and each remains separate within the cytoplasm of the growing hypha. The different nuclei don't fuse together until the mushroom is formed. Then, within the hyphae that makeup the mushroom gills, the millions of descendants of the two original nuclei fuse together and undergo the sexual divisions that produce spores.

Mycorhhizal fungi: Some (but not all) fungi enter into a symbiotic relationship with plants. They envelope the roots of these plants and provide them with more water and mineral nutrients than the roots could get by themselves. In exchange, the plants feed the fungi with sugars produced by photosynthesis in their leaves. It's a partnership in which both members benefit. These fungi are called mycorhhizal, a term that simply means "fungus-root." I don't know why the double "r" is necessary, but that is the way it's spelled in English.

Tall Thistle flower and buds.
Thistles: The first flower encountered was a Tall Thistle, in the Sunflower family (Asteraceae). Unlike the "typical" Asteracea thistles have no ray florets; the flower heads are composed entirely of disk florets. The fuzzy purple projections that give thistle flowers their characteristic look are the forked styles of individual florets sticking up above the tiny corollas. There are a number of invasive thistle species but one way to separate them is by the color of the undersurface of the leaves. Our native thistle leaves have a white undersurface while the non-natives have green undersides. (This is a good rule-of-thumb, but there may be exceptions.)

Cloudless Sulphur caterpillar on Maryland (Wild) Senna.
The Cloudless Sulphur is a common summer butterfly that, like the Gulf Fritillary, is an immigrant to our area from Florida. It cannot survive our winters here in the Piedmont, so our population is renewed each year by migrants from further south. The food plant of the Cloudless Sulphur caterpillar is Senna and on the Wild Senna (Senna marilandica) plants in the power line ROW we found several caterpillars. This website has many photographs of all stages in the life history of the butterfly as well as information about and photographs of its host plants in Florida. (There is also a discussion of the extrafloral nectaries of the host plants!) If you have an interest in this I strongly suggest that you visit the site.


Sleepy Orange caterpillar on Maryland Senna
Notice the tiny droplets on hairs visible against the background.

The Sleepy Orange is a resident butterfly whose larvae also feed on Senna. Their caterpillars are even more cryptically colored than those of the Cloudless Sulphur. Their entire body is green with a narrow white line on each side. When the caterpillar is on the edge of a stem or petiole it looks just like a part of the plant and is very hard to find. We probably overlooked many of them. This caterpillar is covered with many fine, glandular hairs. (A glandular hair secretes a tiny droplet of fluid.) The function of these hairs in this species is not known, but it has been investigated in another species in the same family, the Cabbage White butterfly. In that species the secretion of the hairs is an ant repellant. Because the Senna plant has extra-floral nectaries it attracts a lot of ants, so an ant repellant would be a good thing for a caterpillar to possess. (But there is no such thing as a free lunch in nature: the Cabbage White's secretion that repels ants actually attracts a parasitic wasp that lays its eggs on the caterpillar. Sometimes you can't win.)

Silvery Checkerspot butterfly

Silvery Checkerspot caterpillar
Another butterfly that we often see flying in the Garden, the Silvery Checkerspot, uses the various species of Wingstems as its larval host plant. We located a single caterpillar this morning.

Yellow-collared Scape moths mating. 
Don found a mating pair of Yellow-collared scape moths resting on foliage. (The common name of this species really ought to be Orange-collared. Since there are no rules about common names we can call it that if we want.) This species is in the tiger moth family and belongs to a subgroup called "Wasp moths," named for their superficial resemblance to wasps. The males of related species are known to gather distasteful substances from plants in the genus Eupatorium (Thoroughworts). They store these in the sperm packages that they transfer during mating to their female partner. She uses them to coat her eggs, thus protecting them from predators. Males that collect more of the distasteful substances are better able to attract mates. I've not been able to confirm that the Yellow-collared scape moth does the same thing, but they are related to moths that do, so it seems likely they could have similar habits.

Confusing names: Fritillaries. In our area there are only three species of butterflies that have Fritillary in their common names: Variegated Fritillary, Gulf Fritillary and Great Spangled Fritillary. (There are two other Fritillary species found in the north Georgia mountains.) On previous Rambles this year we have seen only the Gulf Fritillary here in the Garden. These three species share the Fritillary name because they all have an orange-brown coloration with darker spots, similar to the color pattern of a group of Eurasian plants called "Fritillaries." The larval food plant of the Great Spangled Fritillary is exclusively violets; the Variegated Fritillary caterpillars can feed on violets or passion vines, but prefer passion vines and the Gulf Fritillary larvae feed exclusively on passion vines. The Gulf Fritillary is closely related to a group of tropical butterflies called Longwings that also are passion vine specialists.

Margined Blister Beetle
One of the surprises this morning was the discovery of a Margined Blister Beetle, named for an unusual property: their blood contains a caustic chemical called cantharidin. When roughly handled they release blood from their leg joints that will cause blisters to develop on the skin. If ingested, cantharadin produces an effect similar to Viagra on men, but with additional unpleasant side effects. The late biologist Thomas Eisner, in his book For the Love of Insects, tells the story of a French physician, J. Meynier, stationed with a military garrison in Algeria in 1869. A large number of soldiers sought his help, all suffering from the same symptoms: "abdominal pain, dryness of mouth, pronounce thirst, frequent and painful urination, general weakness, depressed pulse rate, reduced arterial pressure, lowered body temperature, nausea and anxiety," accompanied by painful and prolonged Viagra-like effects. Dr. Meynier discovered that all the men had feasted on frog legs they had collected locally the night before. He then went to the nearby swamp and discovered that the frogs had been eating large quantities of blister beetles that were extremely abundant there. Dr. Meynier, as well as other physicians of the time, knew of cantharidin and that it was found in Spanish fly, which is the finely ground bodies of dried Blister beetles. The frogs had eaten the blister beetles and absorbed cantharidin in their tissues and the poison was passed on to the men who had eaten frog legs.

Bowl and Doily spider web enhanced by dew on the silk threads.

The Bowl and Doily spider, much enlarged, resting on the bottom of the Bowl. 
On a cool morning like today, when the air temperature is below the dew point, spider webs become very conspicuous, being covered in dew. Especially common are the beautiful webs of the Bowl and Doily spider, named for the two parts of its web. Uppermost is the Bowl, a cup or bowl-shaped tangle of silken threads, the part that captures prey. Beneath the bowl and separated by a short distance is a flat platform, the "doily" of the name. (A doily is a circular piece of lace used by your grandmother to protect the surface of furniture from being scratched by objects like bowls that were set on it.) The spider clings to the bottom of the bowl above the doily, waiting for tiny insects to be entangled by the threads of silk in the bowl. As her prey struggles to escape they fall to the bottom of the bowl and she bites them, injecting a venom that kills or paralyzes them. She then can suck them dry at her leisure.

Wolf Spider
Wolf Spider eyes (enlarged from above)
There are 8 eyes -- count them!
Wolf spiders have a different, more active way of finding their prey. They do not spin webs and passively wait for their food to blunder into their trap. They hunt, running through the grass root jungles in search of their food. When they find it they fall upon it like their vertebrate namesakes. Such an active lifestyle requires good vision and Wolf spiders have it: eight eyes, a small pair on the top of the head and, in the front, a large pair of eyes with a row of four small eyes beneath. "The better to see you with, my Dear."

Dodder
A bright orange Dodder was seen wrapped around some unfortunate plant. Dodders are flowering vascular plants that are fully parasitic and totally lack chlorophyll, thus their bright orange color. They start life as a rooted plant, but once they sink their haustoria into a host plant, the connection to the ground withers away.

Frostweed 
Two of our three Wingstems (genus Verbesina) are starting to flower. One has small white flowers and is known as Frostweed (V. virginica). In late Autumn/early Winter when we get our first hard freezes the stems of Frostweed split open and thin ribbons of ice curl out. To see these beautiful ice formations you will need to get here before the sun hits the plants and destroys them.
All the plants in the genus Verbesina can be collectively referred to as "Wingstems" because they have long, thin ridges of tissue that run most of the length of the stem. There is some variation in how well developed these "wings" are from plant to plant as well as within the length of the stem of some plants, but most plants clearly have the wings.
Wingstem flowers
The other Wingstem that has started to bloom is Wingstem (V. alternifolia); a little later another yellow-flowered species, Southern (or Yellow) crownbeard (V. occidentalis) will start blooming.

Side veiw of Passionflower showing androgynophore;
from top down: 1) the 3 styles;
2) the ovary; 3) the stamens with their anthers;
f) petals and 5) sepals



Passionflower with down turned styles and Carpenter bee;
the bee can easily brush against both anthers and stigmas.
This is a bisexual (hermaphroditic) flower.
(photo by Dale Hoyt)
Passionflower with upturned styles and Carpenter bee;
the bee will only pick up pollen as the stigmas are too high to be contacted.
This is a male flower and will not produce a fruit because it will not be pollinated.
Passion flower or Passion vine is arguably one of the most beautiful flowers in the Piedmont. It is also one of the most unusual. In the center of each blossom is a structure called an androgynophore (literally, male-female bearer) that bears the five male stamens with their anthers and, above them, the pistil, composed of the ovary and three styles with their club-like stigmas. Each flower opens for one day. The anthers are on the same level, approximately 1/2 to 1 inch above the nectaries at the base of the petals. This distance is just right for large, husky bees to contact the anthers when they visit the flower for nectar, but too large for smaller bees to accidentally pick up any pollen as they visit for nectar. Watch A Carpenter Bee nectaring on a Passion flower. They are the major pollinator of Passion flowers.
When the flower first opens in the morning the styles are pointed upward. In this position they are unlikely to receive any pollen because they are not positioned low enough to contact the bodies of pollinators hunting for nectar in the lower part of the flower. After opening the styles bend downwards in many, but not all plants. In the downward position they are able to contact the backs of the large carpenter bees that are the major pollinators of the Passion flower. Those flowers whose styles remain upright are functionally male-only. The plant and/or its individual flowers can control whether they will be hermaphrodites or males. Why should a flower give up the ability to produce seeds? One reason might be competition between flowers for limited resources. It takes a lot of energy to mature a fruit that contains a lot of seeds. So if there are a lot of flowers already developing fruits on a plant the newer flowers might not have enough energy available to produce their fruits. This idea was tested by cutting the ovary off every flower after it opened in one group of plants. Another group of plants was left undisturbed. At the end of the season the first, ovariectomized, group had produced twice as many flowers as the untreated plants. In addition, the proportion of hermaphroditic flowers in the first group was almost double that of the untreated plants. Because the first group never produced any fruits there was more energy available to produce growth and additional flowers. In the control group (the unmanipulated flowers) the flowers that were setting fruit used more energy, making less available for further growth of the plant. Also, because of the smaller amount of energy available the later flowers were more likely to be functional males and less likely to be hermaphroditic.

Chinese yam (Cinnamon vine)
Note the small tubers like miniature potatoes
 
We also saw several vines of Chinese yam (aka cinnamon vine), a highly invasive Asian species. It can be distinguished from our native wild yams by the presence of small, potato-like tubers in the axils of the leaves

SPECIES OBSERVED:



Common Name
Scientific Name
Mushrooms

Chanterelle
Cantharellus cibarius
False chanterelle
??Hygrophoropsis aurantiaca??
Fragile Dapperling
Leucocoprinus fragilissimus
Fruit

Camellia fruit
Camellia japonica
Flowering plants

Tall thistle
Cirsium altissimum
Wild senna
Senna marilandica
Frostweed/white crownbeard
Verbesina virginica
Woodland sunflower
Helianthus strumosus
Wingstem
Verbesina alternifolia
Tall ironweed
Vernonia gigantea
False nettle
Boehmeria cylindrica
Climbing milkweed/
Eastern anglepod
Gonolobus suberosus
Dodder
Cuscuta sp.
Passionvine/Passion flower
Passiflora incarnata
Small white morning glory
Ipomoea lacunosa
Arrow-leaf tearthumb
Persicaria sagittata
Mild waterpepper
Persicaria hydropiperoides
Carolina horsenettle
Solanum carolinense
Virginia buttonweed
Diodia virginiana
Lurid sedge
Carex lurida
Ragweed
Ambrosia artemisiifolia
Late-flowering thoroughwort
Eupatorium serotinum
Cinnamon vine/Chinese yams
Dioscorea polystachya
Ground ivy AKA Gil-over-the-ground
Glechoma hederacea
Tall goldenrood
Solidago altissima
Insects & Spiders

Cloudless sulfur caterpillar
Phoebis sennae
Sleepy Orange caterpillar
Abaeis nicippe
Wolf spider
Family Lycosidae
Silvery checkerspot butterfly
Chlosyne nycteis
Sheetweb spider (webs)
Stiphidiida family
Bowl and doily spider (webs)
Frontinella communis
Margined Blister beetle
Epicauta funebris
Eastern leaf-footed bug
Leptogolossus phyllopus
Yellow-collared scape moth
Cisseps fulvicollis
Plant hopper
Superfamily Fulgoroidea


 

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