Thursday, July 25, 2013

July 25 2013 Ramble Report

Today was cool and no rain although our ramble on the Purple and Orange Trails was muddy.  Before starting off, Dale read some passages about Sourwood from A Natural History of Trees of Eastern and Central North America by Donald Culross Peattie; the full text follows for your enjoyment:

The glittering leaves of the Sourwood, wondrously fresh-looking and spirited, have completed their growth long before the flowers appear, yet so handsome are the great bouquets of bloom at the ends of the branches that they are not put out of countenance by the splendid foliage but, looking like hundreds of little lilies-of-the-valley, they sway and dance in the warm, friendly wind of late June and early July. In case you have not looked up and seen them, you may soon be made aware of them by the roar of the bees gone nectar-mad at their lips.

When autumn comes, the foliage turns a gorgeous scarlet or orange or crimson, double welcome because the Sourwood in general grows outside the range of the Sugar Maple and the Aspen, and takes their place in the South. Then, especially in the southern Appalachians where Sourwood grows 50 and 60 feet tall, is the season to set out afoot, or on horseback, or in your car, to buy sourwood honey from your country neighbors. Some of them put out little signs along the roadside, but all you have to do is watch for a row of “bee gums” not far from the farmer’s house. For if the southern farmer has hives at all, he has Sourwood honey for sale. Fortunately the blooming period of the Sourwood is just after the fading of the Mountain laurel and Rhododendron whose honeys are poisonous. Their honey the bee-keeper throws away, but he is very careful to store his sourwood honey, for it is the finest, in the opinion of many epicures, in the southeastern states and is not surpassed even by the most tangy sage honey of California.

Sourwood honey is medium-light in color, of heavy body, and slow to granulate. An average flow of as high as 75 pounds per colony from Sourwood has been recorded. Usually the local demand takes the entire crop at prices above the open market, so that Sourwood is a honey like some of the choicest wines of the vineyards of Europe – that is, it practically does not appear upon the market at all and can be had only by those epicures who will journey far to partake of it. One buys Sourwood honey as one buys any such rare product from its producers – not in a commercial spirit, paying for it and carrying away the wares – but with all the due ceremony observed between a collector and a creative artist. You ride up to the cabin door; a woman appears at the barking of the hounds, with children peeping out from behind her skirts, and mountain courtesy requires that you begin, not by stating your business but by telling where you come from. Then you assure her that she has a “right pretty place”; you praise her portulacas, her turkeys, and so, across the landscape, you arrive at her bee gums. Then you ask if she likes Sourwood honey as much as you do. You tell her that you would go far to obtain a little if only you could find somebody who would give up a few pounds of it. When the honey is produced, as it certainly will be, you accept it before asking the price. This will be shyly stated. You may safely pay it for your haggling was all done, by indirection, in your previous parley. And you are paying no more than a fico for nectar and ambrosia.

The very hard wood scarcely enters into the lumber business but is cut locally by farmers for the handles of tools. Once on a time in the days of home medicine, the leaves were brewed as a tonic, and they still, with their pleasant acid taste, quench the thirst of the hot, perspiring mountain climber.

Then Carol read from Nature's Chaos by Eliot Porter and James Gleick, p. 47:

Sometimes people try to create miniature ecosystems, mimicking on a smaller scale what the earth has created on a grand one.  One experiment in the American Southwest has brought thousands of species together in a domed world.  Simultaneously, the national park system is learning a hard lesson.  To support a single large mammal, a cougar or grizzly bear, nature requires hundreds of square miles of an intricate mesh of smaller species.  To support a whole, thriving population of such animals, the better part of a continent may be necessary.  Even the great national parks, it now seems, cannot sustain them.  The populations are dwindling and vanishing.  A stripped-down ecology may be no more plausible than a poet with a brain of a mere million bits.  Our imaginations may have been beggared by the monumental built-up hierarchies required to create the apparently simple manifestation of one herd of buffalo, one stand of dogwood.

As we went by the International Bridge in the International Garden some found a water snake.  Others of us missed it.  We all saw the beautiful Lotus blossoms.

Thursday, July 18, 2013

July 18, 2013, Ramble Report

 by Dale Hoyt

We had a group of 9 today. Hugh started us off by reading a few passages discussing some of the problems Darwin encountered in his study of barnacles. They are from Carol Kaesuk Yoon's book, Naming Nature: The Clash Between Instinct and Science, pp. 70-71:

"I have been struck," he [Darwin] wrote to Hooker, "with the variability of every part in some slight degree of every species:  when the same organ is rigorously compared in many individuals  I always find some slight variability, & consequently diagnosis of species from minute differences is always dangerous."
. . .

The variation he had been searching for, hoping to find.  For in an evolutionary view of life, variation is not only real, it's essential, critical, and exactly to the point.
. . .

But as he noted, while "pleasant to me as a speculatist," this variation was "odious to me as a systematist."  In fact, "Systematic work would be easy were it not for this confounded variation…"  It was the understatement of the (nineteenth) century.

As soon as a person sees life through an evolutionist's eyes, as soon as they see all that confounded variation, all that incipient evolutionary change, their view of the species changes as well  It is not merely mutable; it is ever-changing.  What we see at any moment, we realize, is just a snapshot in time, a moment in the great flux of the long life of its lineage, on its way to diverging into new species.  It's a triumph when this happens, for you have gained great evolutionary insight.  The only problem is now you will have absolutely no idea how to order the living world.  You will have no idea how to decide what constitutes or doesn't constitute a species.  You won't have a clue as to how to decide where one variety, one species ends and another begins.  And that was Darwin's problem [with barnacles].

Terry brought a fold-out pamphlet with pictures of common butterflies found in our area (Butterflies of North Carolina, South Carolina and Georgia: Common and Notable Species by Mark Minno). This looks like a handy reference to carry with you when you're out and about.
We covered the same ground as last week's walk: White trail from the parking lot to the power line, then down to the river and back up the powerline and through the Dunson Garden (to avoid the sun). Here's what we saw along the way:
The Cinnabar Chanterelle mushrooms were still present in abundance, shining like glowing orange flags on the wet, shaded forest floor. It's hard to keep in mind that mushrooms are the "flowers" of a more extensive fungal body that consists of fine threads permeating the soil and, in some cases, enveloping the roots of trees and other plants. We looked for evidence of insect feeding damage on the Chanterelles and found none. This is a mystery to me because when I took a mushroom course at UGA 10 years ago every Chanterelle we found was crawling with fly larvae. That was in late August, early September and a different kind of Chanterelle. On one of the other kinds of mushrooms we found there were a number of fungus beetles, but no fly maggots.

Growing on various fallen tree limbs we found Turkeytail fungi as well as False Turkeytail. (The true Turkeytail has a smooth undersurface whereas the "Not-A-Turkeytail" type have porous under surfaces.

Among the other mushrooms we think we were able to identify were Caesar's Amanita and Berkeley's Polypore (Bondarzewia berkeleyi).

Out in the power line we found a Horse Nettle (Solanum carolinense) in bloom. This plant is in the nightshade family (Solanaceae); other familiar members of this family are tomatoes, potatoes, and eggplant. Many of these solanaceous plants have the same unusual arrangement of the anthers. They are bright yellow and are clustered like a tent around the pistil. The anthers are further unusual in that they do not split open to release their pollen. Instead there is a pore at the end of each anther from which the pollen can emerge. But the flower must be shaken or vibrated to remove the pollen. To get this pollen the bee must engage in "buzz" pollination. It grips the flower with its mandible, curls it body over the anthers and makes a buzzing vibration that shakes out the pollen. The vibration is produced by the flight muscles contracting without causing the wings to move. The pollen is attracted to the bee's furry body because of a difference in electrical charge that is built up as the bee flies, just as you build up static electricity when you shuffle across a rug. The flower and its pollen are negatively charged, the bee carries a positive charge.

Here is a link to a site that has a lot of information about buzz pollination, as well as several videos of bumblebees doing it. Buzz pollination videos.

Another cool thing: there is evidence that bees can determine when a flower has been previously visited. A bee visiting a flower will "discharge" it and subsequent bee visitors can detect the diminished charge, probably because some of their sensory hairs are not as strongly attracted to the bloom.

Avis spotted an Indigo Bunting in the trees and it cooperated by remaining there long enough for everyone to view it through Emily's binoculars. The iridescent blue of the male bird is always breathtaking!

We reviewed the structure of the Passion flower (Passiflora incarnata) flower and how it is pollinated, principally by the large Carpenter Bee (Xylocopa virginiana). Also how each flower can be either hermaphroditic or unisexual male. This condition is apparently determined by how much energy is available to each individual flower; those with adequate supplies become hermaphroditic while those with less energy available become functionally pollen donators only. This is done by lowering the three stigmas to a level where they can be pollinated in the bisexual flowers or allowing them to remain in an upright position where they will never receive pollen ("male" flowers). The decision is made by each flower individually, so one plant can bear each type of flower.

Passionflowers have extra-floral nectaries, a pair of glands at the base of each leaf blade that secrete nectar. This source of sugar is attractive to ants and the ants that patrol plant, looking for nectar and protect the plant by also eating herbivores like small caterpillars that they encounter.

We also saw two beetle species are are associated with passionflowers. One was a bright orange and black. This type of conspicuous coloration is typically associated with either distastefulness or poisonousness; i.e., it's a warning coloration. The passionflower vine contains several compounds that are toxic and/or distasteful. Some of the animals that eat the plant store these chemicals in their body and become toxic or distasteful in turn. (The monarch butterfly has a similar relationship with milkweed plants.)

We saw a single Pearl Crescent; this is a very common and very pretty butterfly. Its larval food plant is various species of asters.

Hugh kept scanning the "Wingstem jungle" under the power line for Goldenrod. It's hard to find it among all the other green stems in the jungle but he did locate a couple of plants that had galls. These particular galls are probably caused by a fly (family Cecidiomyidae for the entomology nerds) that lays an egg in the growing tip of the plant. The plant reacts by producing shorter internodes, so the leaves all bunch together at the growing tip. The larva of the fly feeds on the plant tissues inside the bunched leaves. We've been looking for the gall-forming fly that produces a spherical gall on the stem, but haven't yet seen one in the Garden although we have spotted some around Lake Herrick on the UGA campus.

We also found Wild Senna (Senna marilandica) plants where we first located them last year. They are not yet blooming. Joan also noticed that these plants have extra-floral nectaries!

Many of the same plants that were in flower last week were observed again: Virginia buttonweed, Pokeweed, Wood Sage. Not flowering, but abundant were the Wingstems and the Ironweed. We heard Green Frogs (Rana clamitans) calling and saw two Green Tree fogs (Hyla cinerea), one newly metamorphosed. A new plant in flower was a Red Morning Glory (Ipomea coccinea) clambering up the fence near the gate. On the hillside near the Dunson Garden a Mullein was still in bloom.

It was beginning to get hot so we decided to walk back through the shady Dunson Garden and observed the Hibiscus in bloom. Hugh also discovered a Golden Garden Spider orb web in the Hibiscus. Also seen: newly metamorphosed Spadefoot toad, Royal Fern, Jack-in-the-Pulpit with developing fruits, Clethra in bloom, Rattlesnake Master and a Yellow Wood tree.

While in the Dunson Garden we came across a Black Cohosh that was still blooming. Its tall inflorescence still had a few flowers at the very tip. This prompted Carol to tell us about determinate and indeterminate growth forms. The Cohosh exhibits an indeterminate growth form -- the terminal bud of the flowering stalk continues to grow and new flowers appear from lateral buds below the terminal. The first of these flower bud are the oldest and they open first. Then successive buds higher up the stalk open until the top is reached. Because the flowering stalk can continue to grow and produce more flowers the number of flowers that will ultimately be formed is indeterminate. As good discussion of the kinds of inflorescence and growth forms in flowering plants can be found in this Wikipedia article.

We then adjourned to Donderos' for our usual snacks and conversation.


Thursday, July 11, 2013

July 11, 2013, Ramble Report

First, we had a reading and a show and tell about dodder (Cuscuta gronovii) by Dale Hoyt

The reading is from: Cultivating Delight: A Natural History of My Garden, by Diane Ackerman, 2001, HarperCollins, pp. 75-76

Summer is a new song everyone is humming. From atop a chestnut tree, where spiked fruits hang like sputniks, comes the sound of a bottle band and the kazoo-istry of birds. On the ground, a blanket of dry leaves gives sound to each motion: falling berries, scuffling voles, a skink rising from its bog. Small fence lizards do rapid push-ups as part of their territorial display. All along the weedy roadways, grasshoppers thrash and rustle in the brush, playing mating tunes. Grasshoppers are musical instruments. They sing by scraping a row of . . . pegs on the inside of each back leg against hard ridges on their forewings. Different species have different calls, depending mainly on the arrangement of the pegs. There are alto and tenor grasshoppers, plus a band of crickets and cicadas rubbing shrill songs on their washboards. The grass has grown tall at last, and the trees offer shade for the first time in a year.
. . .
Countless birds seem to be auditioning for their jobs. Large glossy crows sound as if they're gagging on lengths of flannel. Blackbirds quibble nonstop from the telephone wires, where they perch like a run of eighth notes. I sometimes try to sing their melody. Because every animal has its own vocal niche . . . summer days unfold like Charles Ives symphonies, full of the sprightly cacophony we cherish, the musical noise that reassures us nature is going on her inevitable green way and all's right with the world.

Dodder is a parasitic plant that lacks chlorophyll and leaves. Its orange/yellow stems vine across and around its host. Where the vine lies close about the host's stem it sends out haustoria that penetrate the stem and tap into the conductive tissue of the host. The parasite gets all it's nutrition from the host plant.

Not many participants today (8), but the weather held beautifully.  We walked down the white trail from the lower parking lot to the power line right of way and down to the river.  Then walked up the power line right of way to the top of the hill.  There was an amazing number of things to talk about.  In fact we found a spade foot toad in the parking lot before we left.  They must have traveled up into the Garden area from the power line right of way at the river where they started.

The first find was a whole batch of Chanterelle mushrooms.  They lined the trail all through the woods.  A few spade foot toads were still around in the power line right of way by the river.  There were a number of plants of interest: Virginia Buttonweed (Diodia virginiana), Maypop or Passionflower (Passiflora incarnata), and Wood Sage or American Germander (Teucrium canadense).  Dale discussed how the maypop changes to a male or bisexual flower by either holding up its stigmas (male), or by lowering them to be close to stamens so that when bees visit the plant they deposit pollen on the stigma.  In this area we observed how high and fast the Oconee River was flowing and also loaded with silt (red soil).  Because of poor farming practices during the cotton era, the Piedmont has lost 12 feet or more of topsoil through erosion.  The muddy river is still picking up some of that soil and carrying it further downstream.

Two butterflies were seen, even thought the morning was very overcast: a freshly emerged Red Admiral (Vanessa atalanta) and a Pearl Crescent (Phyciodes tharos). We also heard a few isolated calls from a Bronze Frog (or Green frog) (Rana clamitans) in the wetland areas. It sounded like a very nasal "Gulp."

Walking up the power line right of way, a number of plants were discussed:

Queen Anne's Lace (Daucus carota)
Butterfly weed, or chigger weed (Asclepias tuberosa)
Spiderwort (Tradescantia virginiana)
Castor bean             
Bitterweed (Helenium amarum)
Mountain Mint (Pycnanthemum incanum)
Whorled Coreopsis (Coreopsis major)    
Wild Bergamot or Beebalm (Monarda fistuloso)
Rose Pink Sabatia (Sabatia angular)
Crownbeard (Verbesina virginica)
Thimbleweed (Anemone virginiana)
Pineweed (Hypericum gentianoides)
Spotted St. Johnswort (Hypericum punctatum
Sensitive Brier ( Mimosa microphylla)

At the top of the hill it was time to return to the Visitor's Center for snacks and conversation.

On the way back we did take a short detour to see the flowers on the Devil's Walking Stick (Aralia spinosa).  Dale pointed out that the leaf is compound and huge, so huge that it may be the largest leaf in plants in North America.  Next to it was the Anise tree (Illicium parviflorum), also in bloom.