Friday, March 16, 2018

Ramble Report March 15 2018

Today's Ramble was led by Linda Chafin.
The photos in this post, except where noted, came from Don Hunter's Facebook album (here's the link).
Today's post was written by Linda Chafin.
27 Ramblers met today.
Today's reading: Bob Ambrose recited (from memory) Robert Frost's Nothing Gold Can Stay:
Nature's first green is gold,
Her hardest hue to hold.
Her early leaf's a flower;
But only so an hour.
Then leaf subsides to leaf,
So Eden sank to grief,
So dawn goes down to day
Nothing gold can stay.

Today's Route:   We left the entrance plaza at the Visitor Center and headed down the paved path, past the American South bed and across the Flower Bridge.  We passed through the China and Asia Section, the Rare and Endangered bed and across the Native American and Southeastern Tribes section, skirting the Herb and Physic Gardens before arriving at the Heritage Garden.  We then made our way down into the Flower Garden, concentrating on the cherries, crab apples and blueberries before heading back to the Visitor Center.
Cedar Waxwings basking in the sun.

As we gathered at the Visitor Center Fountain Plaza, we noticed a lot of activity in the Palatka Holly trees around the plaza. Many Cedar Waxwings were basking in the sun striking the upper branches, while others were foraging on the holly berries.

Japanese Maple leaf and flower
The Japanese Maples along the Visitor Center sidewalk have partially leafed out and begun to bloom. Maples, both native and exotic, are among the first trees at the Garden to flower. Our native Red Maples flowered in February and have gone to seed. Maples are monoecious, meaning that male flowers (with stamens) and female flowers (with pistils) are found on the same tree. Some maples are functionally dioecious, that is, they act or function as though the male flowers and female flowers are on separate trees. In maples, the male flowers on some trees don’t actually produce pollen, so that only the female flowers are actually functioning.  We looked at several female flowers on the Japanese Maples, their styles protruding out from the small, red flowers, and saw no stamen-bearing flowers, so perhaps this tree was functionally female. Maples are generally thought to be wind-pollinated: their flowers are inconspicuous and open in late winter before most insects are active. But bees do visit maple trees, especially Red Maples and Sugar Maples, to gather nectar so at least some of the pollination is carried out by insects. There is a nice article on Japanese maples at this website:

Redbud showing cauliflory

Redbud flowers

Several Eastern Redbuds are in flower along the path into the International Garden. We stopped to admire the strange phenomenon of cauliflory, where flowers emerge directly from the bark of the branches and trunks of the trees. Some of the Redbud trees planted in the Garden may have been horticulturally selected to maximize cauliflory, but it also occurs frequently in wild trees as well. Cauliflory is mostly found in tropical shrubs and understory trees; Redbud is one of the few temperate species to exhibit this trait. Curious minds want to know: how and why? Studies done in just the last couple of decades have answered these questions. There are two parts to the “how” answer. Redbuds produce in each leaf axil up to ten “first order” flower buds that can remain dormant for up to five years and that flower sequentially on small branches during those five years. But what about the flowers on older, larger branches and even on the trunks? It turns out that first order buds have the ability to produce “second order” buds that go on flowering indefinitely on ever enlarging branches and trunks. And what about the “why” question, so dear to Ramblers, and often so hard to answer? Botanists know that the closest relatives to Eastern Redbud are tropical cauliflorous species, so this ancestral trait was apparently carried along as Redbuds evolved to live in temperate areas. But why cauliflory in the first place? What advantage does cauliflory confer on some tropical plants? Most tropical species with this trait are understory trees, attracting a different set of pollinators than the flowers in the upper reaches of the canopy. So perhaps cauliflory evolved to attract and provide nectar for the low-flying insects, such as heavy-bodied  bees, that never make it up into the canopy. For a more detailed discussion of cauliflory, this is a good article:  “Redbud Cauliflory: The Inside Story,” by John Hayden.

Chattahoochee Trillium with "youngsters"

Virginia Bluebells

Woodland Phlox
Several native wildflowers are flowering along the path into the International Garden, including Virginia Bluebells, Woodland Phlox, and a small “family” of Chattahoochee Trillium, with a large, flowering plant and various two- and three-leaved “youngsters” around its base that will mature and bloom over the next few years. 

Georgia Rockcress

Gerogia Rockcress closeup
There are several beds of Georgia Rockcress in full bloom in the International Garden. This is one of the most endangered species in Georgia, with only a handful of populations surviving in the northwest corner of the state near Rome and in the Fall Line, near Columbus.  They love rocky cliffs and bluffs, or perhaps they inhabit these stressful environments because there’s little competition. They are clearly flourishing in the rich beds at the Garden. Georgia Rockcress is one of the top priority species of the Georgia Plant Conservation Alliance and has also been nominated for federal listing as legally Endangered.

The Flower Bridge is adorned with planters filled with large-flowered pansies, which some Ramblers were surprised to learn are actually cultivars of wild violets (in the genus Viola). The many shapes and colors of pansies are the result of artificial (human-induced) hybridization among several species in the section of the Viola genus called Melanium. Wikipedia tells us that the name pansy “is derived from the French word pensée (thought), and was imported into Late Middle English as a name of Viola in the mid-15th century, as the flower was regarded as a symbol of remembrance.”

The flowering stalk of Grass-leaf Sweet Flag
Planted among the pansies is a strange little plant with grass-like leaves and an erect spike of yellow-green flowers. It turns out to be Grass-leaf Sweet Flag, Acorus gramineus cultivar Ogon. Neither a sedge nor a grass, it's in the Sweet-flag or Calamus family, sister to all the other monocotyledonous plants. It is not native to US; native to Japan, Korea, and Eastern Asia.

The yellow-green spike (spadix) consists of tightly packed little ovaries that will become small red berries, if they are fertilized. Tucked in among the female flowers are tiny male flowers that will present their stamens later to prevent self-pollination.

At the back edge of the International Garden, there is a pretty little groundcover flourishing between the pavers. Known as Cupflower, it’s a white cultivar ‘Alba’ of a creeping species of Mazus.

Alabama Snow Wreath
The large hedge of Alabama Snow Wreath at the entrance to the Threatened and Endangered beds is in peak bloom. This is a beautiful shrub, with long, arching boughs covered with showy white flowers. The flowers have no petals, just a cluster of long, white stamens. Found in Georgia only in two northwestern counties, it occurs naturally in rocky, limestone-based forest soils. It spreads largely by underground stems; seeds are seldom seen. The genus Neviusia has only two species in it, ours (Neviusia alabamensis) and one other in California. It is in the Rose Family.

Pawpaw flowers
The Pawpaw trees
near the entrance to the Heritage Garden are covered with many buds and barely open flowers. Dark maroon in color, the flowers are thought to attract pollinating flies and beetles by a hue that suggests rotting meat. But however pollination occurs, it doesn’t seem to result in much fruit formation here at the Garden or elsewhere. In their article “Pollinator limitation, fruit production, and floral display in pawpaw (Asimina triloba),” Mary Willson and Douglas Schemske state that less than one percent of flowers produce fruit. Looking closely at the open flowers, Ramblers could easily see a well developed green ovary but no stamens, the “female” part of a given flower developing well before the “male” stamens, thereby preventing self-pollination. Perhaps this system works too well? Since Tall Pawpaws grow in large clonal colonies, pollen transferred from their closest neighbors, which are genetically the same plant, won’t result in fertilization. Flies and beetles have to travel long distances between pawpaw patches to effect cross-pollination and cross-fertilization. It is apparently established practice among commercial pawpaw growers to hang a dead animal in their pawpaw patches to encourage pollinators to move around among plants and patches!

Flowers of 'Belle of Georgia' peach
Several large ‘Belle of Georgia’ peach trees were blooming near the edge of the Heritage Garden. Peaches are in the same genus, Prunus, as cherry trees, which are also flowering now. Both have the characteristic bark trait of conspicuous horizontal rows of lenticels, the spongy tissue that allows the plant to uptake carbon dioxide through its bark.

Crabapple cultivar 'Louisa'
One of the Crabapple cultivars, 'Louisa,’ is flowering beautifully now at the edge of the Flower Garden, its sign prompting a discussion of the meaning of “cultivar” and how it differs from the term “variety.” The word “cultivar” is a portmanteau (a word that combines the meanings of two other words, like brunch); cultivar is simply shorthand for “cultivated variety.” A type of plant that has been developed horticulturally by hybridization or other artificial breeding techniques is called a cultivar and given a non-Latin name that is shown in single quotation marks, hence ‘Louisa.’  Usually the cultivar name is preceded by the Latin name: Malus angustifolius ‘Louisa.’

On the other hand, the term “variety” is applied by botanists to a group of plants that differs consistently, perhaps with a different leaf or flower shape, from other plants in that species in ways that suggest that the group is on the way to evolving into a new species. So: variety is used for the result of a natural process and cultivar is used for the result of an artificial process.

Several weedy European wildflowers are flowering now in the edges of flower beds and in sidewalk cracks. These are among the first wildflowers that many of us learned – they are conspicuous and easy to identify, and, though exotic, are not invasive or found in natural areas. Henbit and Dead-nettle are both in the mint family, as their square stems, opposite leaves, and two-lipped flowers testify. Hairy Bittercress has leaves with up to nine rounded leaflets and the sharp odor of plants in the Mustard Family.

Two lichens
Some of the brick walls in the Heritage Garden are covered with patches of gold- and gray-colored lichens, whose identity await the arrival of lichen experts!


Cedar Waxwings
Bombycilla cedrorum
Palatka Holly; hybrid of
two native hollies
Ilex cassine x Ilex opaca
Japanese Maple
Acer palmatum
Eastern Redbud
Cercis canadensis
Chattahoochee Trillium
Trillium decipiens
Virginia Bluebells
Mertensia virginica
Woodland Phlox
Phlox divaricata
Georgia Rockcress
Arabis georgiana
Viola section Melanium
Mazus reptans 'Alba'
Alabama Snow Wreath
Neviusia alabamensis
Primrose-leaved Violet
Viola primulifolia
Dwarf Sumac
Rhus michauxii
Paw Paw
Asimina triloba
Creeping Fig
Ficus pumila
Belle of Georgia Peach
Prunus persica
Flowering Crabapple
Malus angustifolius 'Louisa'
Rabbiteye Blueberry
Vaccinium ashei
Lamium amplexicaule
Hairy Bittercress
Cardamine hirsuta
Several species of lichen

Sunday, March 11, 2018

Ramble Report March 8 2018

Today's Ramble was led by Dale Hoyt.
The photos in this post, except where noted, came from Don's Facebook album (here's the link).
(Note added after posting this page.
Don returned to the Dunson Garden in better (warmer) weather and got some spectacular photos of Trout Lillies and other spring flowering plants. View his album here.)
Today's post was written by Dale Hoyt.
26 Ramblers met today. Introduced were three new ramblers, Susie and John (who joined us last week), and AJC nature columnist Charles Seabrook.

Show & Tell: Sue brought in a Luna Moth cocoon that she recently found in Memorial Park. Luna caterpillars are polyphagic, which means that they eat the leaves of a variety of trees. I've reared them on Sweet Gum, but they have been recorded eating Hickory, Walnut, Maple, Ash and many others. Their preferences vary regionally.

Sunday, March 4, 2018

Ramble Report March 1 2018

Today's Ramble was led by Dale Hoyt.
The photos in this post, except where noted, came from Don Hunter's Facebook album (here's the link).
Today's post was written by Dale Hoyt.
22 Ramblers met today.

Wednesday, March 7, at 9:00 am: Guided walk at Sandy Creek Nature Center led by Dr. Carlos Camp, of Piedmont College. Dr. Camp specialized in salamanders! Snacks and conversation following.

Today's reading: Rosemary read the poem Lost by David Wagoner (link here).
Richard read Advice to Myself by Louise Erdrich (link here).

Today's route: From the visitor center we made our way to the Administration bldg. via the construction parking area. After descending the stairs we walked up the road to the mulched path that connects to the White trail. Turning right on the White trail we then took the next left down to the Dunson Native Flora Garden, walked through the garden to the power line right-of-way, turned left and walked as far as the ephemeral pool. Then we returned to the visitor's center.

Dunson Native Flora Garden.
For the benefit of our new ramblers: the DNFG contains plants that are native to the state and that will grow in this area. Some of the wildflowers, trees and shrubs are not native to the Athens area or the piedmont, but are found growing naturally in Georgia. You can see species here that you would have to drive hundreds of miles to see in their native habitat. 

When different species of related plants grow together they can potentially hybridize. That has happened here with the trilliums. As a result, we find trilliums in the DNFG that have mixed characteristics of several different species. So don't expect that every plant can be identified with confidence.

We also find individual plants that have "escaped" the garden. Trilliums do not naturally occur the Botanical Garden, so if you find any growing outside the DNFG, you're seeing the result of seed dispersal. (In the case of trilliums this is done by ants. More about this later.) Before entering the DNFG we saw a group of these escaped trilliums and inside the garden proper there were more.
Chattahoochee trillium with unopened bud

Chattahoochee trillium with opened bud
Most of these plants had the appearance of the Chattahoochee Trillium: tall stems, mottled leaves with a prominent white or silvery streak along the midvein. A similar looking wildflower, the Sweet Betsy Trillium was also seen. It is shorter than the Chattahoochee and has mottled leaves that lack the dramatic midvein stripe.
Both these species are examples of a group of trillium species called "Wake Robins," or sessile trilliums. (Sessile means attached and refers to the fact that the blooms seem to be sitting on top of the leaves.)
The other group of trilliums have flowers that are not sessile – the flower is supported by a stem that separates the flower from the leaves below it. This condition is called a "nodding" trillium.
Georgia Dwarf trillium
One of the nodding trilliums, a Georgia Dwarf Trillium is currently blooming. It has only recently (February, 2017) been recognized as a new species, distinct from the other dwarf trilliums. It is only found in one location in Whitfield County, northwest Georgia. The plants in the DNFG were rescued from a site that is due for development in the future.

Cranefly Orchid leaves are purple on the underside but normally "green side up."
Cranefly Orchid leaves are still to be found. The single green leaf has a pleated appearance and if you turn it over you will discover that the undersurface is colored an intense purple. This orchid has an unusual life history. The orchid leaf emerges in the fall and lies flat on the bed of newly fallen tree leaves. The lack of a tree canopy enables the orchid leaf to carry out photosynthesis during the winter, although it is limited by temperature. When spring arrives and the canopy closes the single orchid leaf will wither away. If it stored enough energy during the winter the plant will send up a flowering stalk in the middle of summer. The stalk bears dozens of tiny tan flowers that resemble an insect known as a crane fly, hence the common name, Cranefly Orchid.

Early Spring Flowers.


Virginia Bluebells; as the flowers age
they turn blue.

Halberd-leaved Violet

Rue Anemone

Spring Beauty

Cutleaf Toothwort

Common Blue Violet
Early spring flowers take advantage of tardy trees. Most of the tree species in eastern North America do not leaf out early in the season. This gives a literal opening to the flowering plants. If they bloom early they can bask in the early spring sunshine unobstructed by tree leaves. This allows them to gather enough sunlight energy to produce flowers with their pollen and seeds. But they have to hurry, because soon the trees overhead will block the sunlight and the plants on the ground beneath will be starved of the suns energy. When the tree canopy closes many of the early spring plants allow their leaves to wither and enter a state of dormancy, existing only as an underground storage organ, a bulb, root, corm or rhizome.

These early spring flowers must somehow scatter their seeds. Many of them rely on ants for dispersal. To entice the ants the plants produce seeds with a nutritious handle, called an elaiosome (pronunciation: e-LIE-o-som). This is a fat and protein rich handle on the seed that ants love. The ants carry seeds with elaiosomes back to their nest and feed the elaiosome to their larvae. The left-over seed part is carried to the ant colony's waste disposal location and dropped among the bodies of deceased ants and ant poo. In this nutrient rich environment it can germinate and grow vigorously. Among the plants that produce seeds with elaiosomes are violets, Bloodroot, trilliums, spring beauties, bleeding hearts and dutchman's britches, most of which can be found in the DNFG.

Golden Ragwort; Aster family
note the kidney shaped lower leaves;
seeds are wind dispersed, like dandelions

Golden Ragwort
Highly dissected leaf on the flowering stalk.

Ephemeral pools form in low lying areas as a result of heavy rains. If the pools form in the spring they are often called vernal pools. At other times of the year they are simply called temporary pools. Collectively, they are ephemeral pools. These small wetlands are temporary and, depending on weather, last from a few weeks to a month or two. One such pool regularly forms in the lower power line right of way on the west side between the path and woods. In early February of this year this pool formed and immediately attracted at least three kinds of amphibians: I heard the calls of Southern Leopard frogs, American toads, and Spring Peepers. Males arrive first and begin shouting their characteristic mating vocalizations. The leopard frogs make a grunting, chuckling noise from under water. American toads issue a lengthy trilled call and the spring peepers produce a whistled "peep." You can hear recording of all these species on the internet.
Several egg masses of Southern Leopard frog fused together;
each black dot is a single egg
(photo by Emily Carr)

Southern Leopard frog, American toad and Spring Peeper.
Frogs face some difficult decisions in selecting a place to breed. Permanent bodies of water are dangerous. They contain fish and dragonfly larvae, both of which prey on tadpoles. Ephemeral pools are safer because they are not permanent. When they dry up all the living inhabitants either die or enter a resting stage. Fish don't have such abilities and neither do dragonfly larvae. But the trade off is that the ephemeral pool is impermanent. It may not last long enough for the tadpoles to complete metamorphosis. Additional dangers arise from where the eggs are laid. If the water is too shallow the egg masses will be exposed and dry out before they can hatch. That has been the fate of many Leopard frog egg masses that we have seen deposited in this pool over the years. The mortality rate is high and only a small percentage of tadpoles survive through metamorphosis into frogs or toads.
Tadpoles (three weeks later)
These could be American toad or Southern Leopard frog tadpoles.
(photo by Rosemary Woodell)
Rosemary found many dark colored tadpoles swarming about in the pool edge. They are hard to identify without examining their mouthparts under a microscope. Since they were clustered together a good guess would be American toad, since tadpoles of that species are known to aggregate. But they could also be Southern Leopard frogs, because we saw their egg masses just three weeks ago.
Two Ostracods, greatly magnified

I scooped up a water sample from the pool and was surprised by two things: I didn't find any mosquito larvae (I did three weeks ago) and I got dozens, if not hundreds of tiny ostracods. Ostracods are a type of crustacean found in both marine and freshwater. They look like tiny clams that are able to swim about. They range in size from about 1/125th of an inch to 1/8th of an inch. They are grazers, feeding on bacterial films and decaying organic matter on surfaces under water. The ostracods I found are on the very tiny side.
Mosquito on Blueberry flower

Male Mosquito on Georgia Dwarf Trillium
Speaking of mosquitoes, no one complained of being bitten today, but many mosquitoes (or similar-looking harmless midges) were seen flying about. Don got a photograph of a male mosquito on a Georgia Dwarf Trillium. You can tell that it's a male because it has very bushy antennae. In mosquitoes both sexes feed on nectar; only the female feeds on blood. She requires a blood meal in order to make her eggs. It is also the female that makes that annoying "hum" you hear when you're trying to go to sleep. The female's antennae are much less bushy than the males. That's because the hum is a mating signal and the antennae are the "ears" of the mosquito.


Sanguinaria canadensis
Cranefly Orchid
Tipularia discolor
Chattahoochee Trillium
Trillium decipiens
Trillium species
Trillium sp.
Galium aparine
Golden Ragwort
Packera aurea
Dirca palustris
Georgia Dwarf Trillium
Trillium georgianum
Virginia Bluebells
Mertensia virginica
Lindera benzoin
Cutleaf Toothwort
Dentaria laciniata
(= Cardamine concatenata)
Carolina Spring Beauty
Claytonia caroliniana
Rue Anemone
Thalictrum thalictroides
(= Anemonella thalictroides)
Halberd-leaved Violet
Viola hastata
Common Blue Violet
Viola sororia
British Soldier lichen
Cladonia cristatella
Highbush Blueberry
Vaccinium corymbosum
Ostracods, Unspecified
Class Ostracoda
Tadpoles of Southern Leopard Frog or American Toad
Lithobates sp. (Leopard frog) or Anaxyrus americanus (American toad)
Ground Ivy
Glechoma hederacea
Purple Deadnettle
Lamium purpureum
Common Chickweed
Stellaria media
Hairy Bittercress
Cardamine hirsuta