Ramble Report March 23 2017

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.)

Today's post was written by Dale Hoyt and Don Hunter.

Twenty Ramblers met today.

Today's reading: Linda read Weather by Faith Shearin. You can find it here. Linda also thought that Ramblers would find this piece about the benefits of walking in nature of interest.

Announcements: Guided walk at Sandy Creek Nature Center 9:00 a.m., Wednesday, April 5.  Mike Wharton will be leading a walk through the areas recently cleared and planted as part of the managed forest project at the center. (You can always check our Announcements page for the latest information about upcoming events.)

Today's route: On the other side of the parking area to examine a Red Buckeye, the down the mulched path to the Dunson Native Flora Garden. Then through the garden at our usual "speed of botany."

Frost damaged leaves and male cones of Ginkgo

Frost Damage

The WeatherSTEM unit at the Garden recorded a hard freeze for three straight nights in March (15, 16 and 17); temperatures reached 27°F for many hours. The peach and blueberry crops in Georgia suffered severe damage and at the Garden we see damage to some of the trees that had already leafed out: the Ginkgos at the Arbor and one of the Japanese Maples. Strangely enough, the Red Maples around the parking area didn't seem to be affected.

Red Maple samaras

Red Maple

Linda passed around a Red Maple twig with developing fruits. Long, slender red stalks dangled from the twig, each one bearing a pair of maple fruits at its end. Linda remarked that the Red Maple offers us something red in every season: the red flower in later winter and early spring, the red leaf stalks in the summer and the leaf that turns red in the fall.

If you're confused about what a maple fruit is, remember that a fruit is what botanists call the thing that holds one or more seeds of a flowering plant. The maple seed is enclosed at one end of a wing-like structure and each flower can produce two seeds, each enclosed in what looks like a wing. The whole thing, wing plus seed, is called a samara. When the fruit is ripe is drops from the plant and whirligigs like a helicopter to the ground. If the wind is blowing when the samara falls it will be carried a considerable distance from the tree. In my neighborhood there is a Red Maple that flowered early in February. It's fruits developed rapidly during the warm weather of that month and were ripe just before last week's violent thunderstorm hit. The following day the entire tree was stripped of fruit and I couldn't even find any on the ground, either under the tree or nearby. The winds had been strong enough to denude the tree and blow all its fruit away. The wing of the samara had done its job.

Red Buckeye flower buds

Painted Buckeye early flower buds

Closeup of Red Buckeye flower
These flowers are very attractive to hummingbirds.

Red Buckeye

Across the parking area, near the Administration building are several Red Buckeyes that have leafed out and also have developed several clusters of red flower buds. Each flower is an elongate cylinder that will open at the end, inviting the Ruby-throated hummingbird to sip its nectar. To get the nectar the hummingbird inserts its bill deep enough the reach the base of the flower and, in doing so, it picks up pollen from the stamens inside the upper portion of the flower. When it visits another buckeye flower the pollen will brush off on the stigma as the bill enters the flower.

The Red Buckeye is not native to this part of Georgia. It is confined to the coastal plain. There is another, similar, buckeye species that grows in the piedmont of Georgia and the Carolinas: the Painted Buckeye. It has similar shaped flowers but they are yellow in color. In natural areas of the Georgia piedmont you can find buckeyes with orange flowers. These are hybrids between the Red and Painted Buckeye. Back in the 1980s a UGA graduate student and his professor (Claude DePamphilis and Dr. Robert Wyatt) suggested that hummingbirds could carry pollen from Red Buckeyes northward to the piedmont during their northward migration from Mexico and Central America. Indeed, the dates of arrival of hummingbirds in the piedmont in those years corresponded with the flowering times of the Red and Painted Buckeye. As our climate warms it is possible this flow of pollen could be interrupted if buckeye flowering and hummingbird migration become out of phase with each other.

Ephemeral Spring Flora

In eastern North America there are a group of species found in the herbaceous layer of vegetation that appear early in spring, flowering, producing seed and then disappearing when the leaves appear on the trees overhead and the canopy closes, reducing the sunlight they require to reproduce. They persist underground from year to year as bulbs or other types of underground organs: rhizomes, corms, etc. Examples of plants with this lifestyle are hepaticas, bloodroot, trilliums, wild gingers, shooting stars, wood poppy, dutchman's breeches, trout lilies, wild geranium, mayapples, etc. Strictly speaking, to be a spring ephemeral all above ground evidence of their presence must vanish after the canopy closes. But the leaves of some plants, like bloodroot and hepatica, considered to be spring ephemerals, persist throughout the summer and winter, dying only the following spring.

Another feature that many spring ephemerals share is reliance on ants to disperse their seeds. These plants produce seeds with a fatty, protein rich appendage called an elaiosome. (Some examples of elaiosomes can be seen here.) When foraging ants discover such a seed they grab the elaiosome with their mandibles and carry it and the attached seed back to their nest. There other ants cut off the elaiosome and feed it to the ant colony's developing brood. The seed is picked up by the colonies sanitation ants and discarded at the colony's refuse area along with other ant refuse and trash. Here the seeds find a rich compost in which to germinate and produce a new plant. Depending on the ant species, the seeds may be carried a considerable distance. In area surrounding the Dunson garden you can find trilliums hundreds of feet from their likely parents.

(For collectors of abstruse technical terminology: the term for dispersal of seeds by ants is myrmecochory.)

Trilliums

There are trilliums blooming all over the Dunson Garden today. Many species have been planted in the Dunson garden and over the years they have a tendency to hybridize, so you will often find specimens that don't look quite like what you expect. They also have been very successful in dispersing themselves around the garden as well as some distance from where they were originally planted. Following is a summary of trillium characteristics needed for identification.

Erect or decumbent stems

Most of the trilliums in the Dunson garden have stems that emerge straight up from the ground. In a few species the stems grow along the ground surface for some distance before turning upward and producing a flower.

Sessile vs. stalked flowers

The flowers of some trilliums seem to sit atop the leaves. This condition is termed "sessile," which means directly attached with a supporting stalk. The sessile flowered petals are straplike and vary in color from yellow to dark brown or bronze. They sometimes have an unpleasant odor which is thought to attract flies as pollinators. The trilliums with sessile flowers are often called "toad shades." The petal bases of some sessile-flowered trilliums are narrowed, allowing you to see other flower structures (stamens) between them.

The trilliums that have a flower stalk between the flower and the leaves are called stalked or "nodding," because in many species the stalk bends downward so that the flower is carried below the leaves.

Examples of sessile trilliums:

Chattahoochee trillium

Chattahoochee trillium is tall and the leaves have a silver stripe that runs down the midvein. It is found only in a few counties along the Chattahoochee river.

Underwood's trillium looks like a short Chattahoochee trillium. It has a more widespread distribution, occurring in Georgia, Florida and Alabama.

Spotted trillium

Spotted trillium is tall, like the Chattahoochee, but lacks the silver stripe on the leaf midvein; the leaves are mottled with different shades of green. The petals vary from yellow to brown in color and are narrow at their base creating a gap through which you can see the stamens.

Sweet Betsy trillium

Sweet Betsy trillium is widespread in the mountains and resembles the Chattahoochee trillium, but is shorter and lacks the silver stripe along the midvein.

Decumbent trillium

Trailing/Decumbent trillium has stems that grow along the ground and then turn upward, bearing the leaves and sessile flower just above the leaf litter.

Examples of stalked trilliums:

Georgia Dwarf trillium

Georgia Dwarf trillium is a newly described species of nodding trillium. Originally it was treated as a variety of the Dwarf trillium (Trillium pusillum var. georgiana) but is now recognized as a distinct species.

Persistent trillium

Persistent trillium is another small, white flowering trillium. Linda likes to call it Edna's trillium, after Edna Garst, a long time resident of Athens who discovered it. Edna and John Garst owned property near Toccoa, where they first noticed this trillium growing.  It didn't match any known species of trillium and the Garsts brought it to Dr. Wilbur Duncan's attention., who described it as a new species of trillium and named it the persistent trillium.  He named it persistent trillium because the leaves remain well into the summer, long after the leaves of other trilliums have disappeared.  This is an example of a trillium with the flower on a stalk and the flower is white, unlike the maroon-colored flowers of the sessile species.  It can be seen in the wild on the south rim of the Tallulah Gorge

Dimpled Trout lily

Trout lilies

There are two kinds of trout lilies in the Dunson garden: American trout lily and Dimpled trout lily. The former is represented by the large colony of mostly single-leaved plants massed at the base of a tree. The colony is formed by stolons produced by each corm, a bulb-like underground structure that persists from year to year. Only a small fraction of the hundreds of individual plants in this colony produce flowers. The rest bide their time, storing up starch in their corm until there is enough to support the growth of two leaves and a flower.

The dimpled species does not form large colonies; individual plants can be found elsewhere in the garden. This lack of colony formation is because the dimpled trout lily corm does not produce stolons. large colonies – is due to the presence or absence of stolon formation by the underground corms. Each corm produces a single leaf until it stores enough energy to flower, then it produces two leaves and a stalk with a single flower.

American trout lily: base of inner tepals with tiny lobes; end of fruit rounded without a depression.

Dimpled trout lily: inner tepals lack ears; end of fruit blunt with a small depression.
(Tepals are a term used in plants where the sepals and petals are indistinguishable. You can think of them as petals.)

Golden Ragwort

Green-and-Gold

Golden ragwort and Green-and-Gold are both in the Aster family. What appears to be a single flower with yellow petals and a yellow disk is, in reality, a collection of florets (tiny flowers). Each floret in the outermost circle of florets has a single, yellow, strap-like petal. Each of the inner florets that make up the disk has a tiny, trumpet shaped, yellow corolla (fused petals). With a hand lens you can the anthers inside each corolla and, inside the circle of anthers, the tip of the single pistil (the female part of the flower). Each of the florets, if pollinated, will produce a single seed. In the case of the ragwort the seed will have attached a packet of fuzz that allows the wind to carry the seed away to another location. Green-and-Gold produces seed without any parachutes – it is simply shed to the ground.

Early Meadow Rue; female flowers

Early Meadow Rue; male flowers

Early meadow rue is still blooming. The sexes are on separate plants. Dioecious is the technical term for this condition. Dioecious species cannot self-fertilize and avoid the problems that arise from that type of inbreeding. The other side of the coin is that any plant that is not near a member of the opposite sex will have trouble reproducing.

Plants have a variety of ways in which the sexes are distributed among individuals plants and flowers; here are some of the arrangements:

Hermaphroditic: Each flower on a plant is perfect (has both male and female parts).

Dioecious: Male and female flowers occur on different plants.

Monoecious: Separate male and female flowers occur on the same plant.

Andromonoecious: Male and perfect flowers occur on the same plant.

Gynomonoecious: Female and perfect flowers occur on the same plant.

Each of these arrangements seems to be associated primarily with avoiding self-fertilization. Even in the hermaphroditic case the male and female portions of the same flower often mature at different times. So when the anther is shedding pollen the pistil of the same flower is unreceptive. Since most animals are dioecious self fertilization is not possible. Inbreeding can only occur when closely related individuals mate.

Dwarf pawpaw flower

Dwarf paw paw is currently flowering. The tiny flowers resemble, except for size, those of the real Paw paw (Asimina triloba), which are dark maroon and are said to have a yeasty odor. Flowers with this color are usually pollinated by flies and the coloration is thought to resemble that of rotting flesh. Other types of flies, like fungus flies, are attracted to the odor and might be effective pollinators. Some people with paw paw patches hang road-killed animals from the branches to increase fruit production.

Seersucker sedge

Linda pointed out a clump of seersucker sedge, with it's distinctive pleated foliage. The name is a reference to a fabric, seersucker, that was a staple of Southern summer fashion before the advent of air conditioning.  The dark purple male flowers adorn the tips of the flower stalks, with the yellowish female flowers found at intervals lower on the flower stalk beneath the male flower.

Violets

Three-parted Violet

This Three-parted violet is growing near the Persistent trillium in the Dunson garden and they have been found on the Orange Trail in in previous years.

Violets are divided into two groups based on whether or not the flower is born on a leafy stem. The Common blue violet in your yard has a flower that is carried by a leafless stalk that grows directly from the rhizome. Such violets are called acaulescent, meaning stemless. In the other category of violets, caulescent or stemmed, the rhizome sends up a leaf bearing stem that also bears one or more flowers. The Three-parted violet is a stemmed or caulescent violet.

Violets have a nifty way of dispersing their seeds. They combine the ballistic method with myrmecochory – that is, they explosively expel their seeds, each of which carries an elaiosome. As the seed capsule matures it splits into three parts, each with a few shiny brown/black seeds attached down the middle. As the capsule structure dries out each part pinches its contained seeds. The pinching pressure increases until the seeds are explosively separated from the capsule wall. They can be ejected six feet or more. This mechanism is like something you may have done with watermelon seeds when you were a child. You gripped the seed between your thumb and the first joint of your index finger and pinched has hard as you could. The seed was slick and if you held it correctly it squirt out of your fist at pretty high velocity. When I was a kid we held contests to see who could squirt one the furthest. When we tired of that had watermelon seed wars, of course.

Columbine; nectar spurs are at the top.

Columbine is an early spring perennial. It faces downward and the long, red spurs produce nectar. Hummingbirds seek this out, but to get it they must hover under the flower and tip their head up to insert their bill into the spur.

Tulip tree flower bud
Bud scales starting to fall off,
exposing the bud inside.

Tulip tree

The thunderstorm last week knocked down this flower bud from one of the large tulip trees in the Garden. The flowers are usually so high up in the tree you can't examine them. Your only chance for a closer look is violent winds or squirrels – they seem to enjoy cutting off the flowers for unknown reasons.

Coral honeysuckle flowers, a hummingbird favorite!

Coral Honeysuckle is a vine with red tubular flowers that are very attractive to hummingbirds. This is a native, non-invasive honeysuckle that can be planted without fear of destroying your home environment.

For more pictures of flowers seen today visit Don Hunter's facebook album: Here's the link

Summary of Observed Species

Japanese maple	Acer palmatum
Black cohosh*	Actaea racemosa
Southern maidenhair fern	Adiantum capillus-veneris
Red buckeye**	Aesculus pavia
Painted buckeye**	Aesculus sylvatica
Sharp-lobed hepatica	Anemone acutiloba
Columbine	Aquilegia canadensis
Dwarf paw paw	Asimina parviflora
Cut-leaf toothwort	Cardamine concatenata
Seersucker sedge	Carex plantaginea
Green-and-gold	Chrysogonum virginianum
Carolina spring beauty	Claytonia caroliniana
Shooting stars	Dodecatheon meadia
American trout lily	Erythronium americanum
Dimpled trout lily	Erythronium umbilicatum
Ginkgo	Ginkgo biloba
Wild ginger**	Hexastylis arifolia
Largeflower heartleaf**	Hexastylis shuttleworthii
Dwarf crested iris	Iris cristata
Tulip tree	Liriodendron tulipifera
Coral honeysuckle	Lonicera sempervirens
Virginia bluebells	Mertenisa virginica
Allegheny spurge	Pachysandra procumbens
Golden ragwort	Packera aurea
Woodland phlox	Phlox divaricata
Mayapple*	Podophyllum peltatum
Celandine/wood poppy	Stylophorum diphyllum
Early meadow-rue	Thalictrum dioicum
Rue anemone	Thalictrum thalictroides
Sweet Betsy trillium	Trillium cuneatum
Chattahoochee trillium	Trillium decipiens
Trailing/decumbent trillium	Trillium decumbens
Georgia dwarf trillium	Trillium georgianum
Spotted trillium	Trillium maculatum
Edna's trillium	Trillium persistens
Underwood's trillium	Trillium underwoodii
Perfoliate bellwort	Uvularia perfoliata
Common blue violet	Viola sororia
Three-parted violet	Viola tripartita
*not flowering
**Flower buds