Today’s Ramble was led 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 Linda Chafin (plants) and Dale Hoyt (animals).

Today’s Focus:See what’s blooming in the power line ROW.

28 Ramblers met today.

Announcements:

1)    
Next Weds., Sept. 5, at 9 am there is a Nature
walk at Sandy Creek Nature Center (the Center, not the park). It will be led by
naturalist Carmen Chanpagne. Coffee and refreshments to follow.

2)    
Today is Don Hunter’s birthday. Don is our
co-leader

that most of you know from his beautiful photographs that document
each Ramble. But Don does more than the photography. During each Ramble he
keeps a meticulous record of the things we observe and the discussions we have.
He also prepares the list of observations for each Ramble – you can find them
at the end of each post. All this, plus processing his photographs, takes hours
of his time. We are immensely grateful to Don for all his efforts in making our
Nature Rambles what they are.

Today’s reading:
Eugenia read a poem
by Patricia L. Goodman. It was especially appropriate for the hard of heron.

Show & Tell:

Anglepod Milkvine with flowers

Kathy brought a piece of Anglepod Milkvine to share. Anglepod is the most abundant
of Georgia’s eight species of milkvines. Its common name derives from the shape
of the fruit, which resembles a large, angled okra pod. In spite of the
presence of the toxic white latex that characterizes the leaves of most plants
in the milkweed family, Monarchs do not use milkvines as host plants for their larvae.

Aphids on Anglepod Milkvine, possibly Aphis nerii, the Oleander Aphid. The light colored objects with black legs are the cast off exskeletons (“skins”) that are periodically shed as the aphid grows.

A closer look at the Anglepod revealed numerous tiny orange aphids on the leaves. These may be the same kind of aphids that infest milkweeds, the Oleander Aphid. They reproduce parthenogenetically, giving birth to live nymphal aphids that molt several times before maturing sexually and reproducing like their mother.  Like other insects with piercing, sucking mouthparts that feed on milkweeds they can avoid tapping into the latex channels of the Milkvine. Their mouthparts are quite flexible and are able to steer around the plant cells until they sense the presence of a phloem cell, which they stab. (Phloem cells are the part of a plant’s vascular system that carries newly synthsized sugars from the leaves to the rest of the plant.) The aphids are so good at penetrating phloem that plant physiologists use them as syringes. They allow them to start feeding and remove the aphid, leaving just its mouthparts inserted into the phloem cell. They can then suck up a sample of the phloem cell’s contents through the imbedded mouth parts.

 

Fragrant Lady’s Tresses orchid

Sheldon, the curator of the plants in the plaza area,
planted Fragrant Lady’s Tresses in a pot near the fountain. Its white flowers
are wrapped in a tight spiral around the stem in a pattern that resembles a
braid. The flowers are just beginning to open, and will eventually reveal a
small downcurved lip marked with yellow or pale green.

Today’s Route:  
We left the Visitor Center, and headed down the paved road towards the
White Trail crossing leading up to the ROW, where we made our way over to the
Piedmont prairie plot.  From there we
headed up the hill in the ROW as far as the service road at the top of the
hill, before returning to the Visitor Center for conversation and refreshments
at the Cafe Botanica.  

Cluster of Red Buckeye fruits; each holds one or more large seeds.

A Red Buckeye leaf with five palmately arranged leaflets.

Red Buckeye
fruits are nearing maturity and will soon split open to reveal three large,
shiny, brown seeds. The seeds are highly toxic to humans and livestock and
probably wildlife. (Buckeyes are sometimes called Horse Chestnuts but they are
not related to the true Chestnut which bears edible seeds.) Why would a plant
produce poison fruit? Isn’t the point of fruit to attract animals that will
disperse the seeds after eating the fruit? There is a theory that may apply to
Buckeyes: it holds that large fruits with hard seeds, like the Buckeye’s
fruits, evolved to be eaten in one large gulp by huge animals that are now
extinct, such as giant sloths and American camels. This idea was proposed in a
1982 paper by Dan Jansen and Paul Martin, and expanded into a book by Connie
Barlow called Ghosts of Evolution; click
here to download a pdf file with a nice, short summary of this theory. It is pure speculation on my part, but
perhaps some of these large, extinct animals were not only able to gulp down
the large fruits but were also able to metabolize the Buckeye’s toxic
compounds?

Red Morning Glory

Red Morning Glory
may or may not be native to the southeast – debate rages on – but we enjoyed
its small, scarlet flowers anyway. Morning Glory flowers in general attract
long-tongued bees, such as bumblebees, and hummingbirds and butterflies, and
this may be the case with this species, though we did not see any pollinators
today.

Smooth Spiderwort; still blooming this late in the year.

Smooth Spiderwort
is still flowering. Online sources say it blooms April–July, but it seems to be
hanging in there through this summer’s heat and dry spells. The flowers last
only a day, after which they melt away or deliquesce.

Yellow Crownbeard showing the wings on the stem and the opposite arrangement of the leaves. The scientific name is Verbesina occidentalis. You can remember this because “occidentalis” begins with an “o,” just like opposite.

Yellow Crownbeard,
with its opposite leaves and conspicuously winged stems, is just beginning to
flower. Although the Garden struggles to keep this aggressive native in check,
we don’t want to eradicate it totally since it is the host plant for two butterflies: the Silvery Checkerspot and the Pearl Crescent.

The Science & Conservation program at the
Garden received a grant several years ago to carry out trial plantings in the
powerline right-of-way. The results of these trials will help us convert the
Bermuda- and Fescue-dominated area of the right-of-way to a species-rich
Piedmont prairie. Most of the plants that were planted have flourished,
including Mountain-mint, Appalachian Bergamot, Silver Plume Grass, Spotted
Bee-balm, Late-flowering Thoroughwort (Late
Boneset), and
Yellow Indian-grass. Some other natives have shown up on their own, including
Purple-top Grass and an aggressive, clump-forming sedge sometimes called
Green-white Sedge (though not by me.) A few invasives have shown up also: Vasey
Grass, Crab Grass, and Sicklepod are the most conspicuous.

Sicklepod flower

Sleepy Orange butterfly caterpillar on Sicklepod The actual length of the caterpillar is less than an inch.

Stinkbug on Siclepod leaves The “bug” at center top is just the shed exoskeleton of the bug at lower left. A careful look reveals the split in the top of the exoskeleton through which the bug crawled out. Bugs shed their exoskeletons so they can grow.

Silver Plume Grass growing in the prairie plot. The height of the grass exceeds 8 feet.

Silver Plume Grass flowers The light colored objects are pollen containing anthers; the tiny black flecks are the stigmas that catch pollen blown by the air past the flowers.

The sedge prompted a discussion about what is a
grass versus a sedge versus a forb versus an herb, etc., etc. Some quick
definitions:  An herb is any soft-tissued
plant (i.e. not a woody plant) such as  wildflowers,
ferns, grasses, and grass-like plants such as sedges and rushes. Forbs are a
sub-group of herbs and are everything but the ferns and the grass-like plants.
Grasses, sedges, and rushes are lumped together into a group called “graminoids,”
which just means grass-like. None of these terms are taxonomic—meaning they
don’t relate to the official naming of plants, nor do they tell us anything
about the evolutionary relationships of groups of plants, as taxonomy tries to
do. But they are useful terms especially for ecologists. It’s a bit like calling
groups of people “blondes” or “redheads.”

Spiny-backed Orbweaver

Late Boneset with Ailanthus Webworm Moth

Immature Preying Mantis; the wings are just pointed pads.

White Crownbeard is currently blooming

White Crownbeard
is also coming into flower and will bloom up until cold weather, when it may produce
“frost flowers” when the temperature drops below freezing. More
information about frost flowers is here.

Little Bluestem

Little Bluestem
is one of the later grasses to flower, usually in October. Its lovely blueish
green leaves and the maroon and blue-green banded stems are highly visible now.

Purple-top grass; notice the waxy surface of the florets

Purple-top
or Greasy Grass gets its name from
the purple, waxy (“greasy”) florets that make up its flower cluster. The tiny florets
are held on slender, drooping branches in the cluster. Johnson Grass, bane of
farmers, ranchers, and native plant lovers, is also flowering now along
roadsides–its large flower cluster also has a reddish or purplish hue, but its
branches are held parallel to the ground or angled upward. It is a large,
coarse grass compared to the delicate Purple-top.

Flowering Spurge

Flowering Spurge
flowers look like the drawing a child might make of a typical flower with five
white petals. But they’re not so simple. These are actually clusters of many
tiny flowers in an arrangement unique to the Spurge Family called a cyathium. In the center of what looks
like a single flower there is a small green cup holding one female flower that consists
of only one ovary. If you look closely you can see that the ovary is
three-lobed and topped with a three-parted stigma. Next to it are several male
flowers, each consisting of only a single tiny stamen. (You really need a hand
lens to see these, or a close-up photo). Neither female nor male flowers have
petals or sepals. So, if there are no petals, what are those white things? They’re
glands! Attached to the rim of the cup, there are five tiny green glands with showy
white appendages that attract pollinators. Bees, wasps, flies, and small
butterflies are drawn by the appendages to the nectar produced by the glands.

Elephant’s Foot

Elephant’s Foot
flower heads have several pink disk flowers subtended by three triangular
bracts. Unlike most Aster family flower heads, there are no ray flowers.
Instead the showy, deeply lobed disk flowers call in the insects.

Ebony Spleenwort

Ebony Spleenwort
is one of the few ferns in Georgia that can handle the high light and heat of
the powerline right-of-way.

Enlarged view of Beaked Panic-grass florets showing the “beaks.”

Beaked Panic-grass
is abundant in the right-of-way. Each tiny floret is tipped with a “beak.”

Downy Lobelia

Downy Lobelia
is one of 17 Lobelia species in
Georgia and gets its name (both common and scientific) from the tiny stiff
hairs that cover the stems. Our Lobelias
all have blue, purple, or white flowers except for Cardinal Flower, with its
bright red flowers.

Carolina Milkvine flower (© Alan Cressler)

Inspired by Kathy’s Anglepod
Milkvine specimen, ramblers set off in search of the Carolina Milkvine that
grows in the upper part of the Nash Prairie. We found plenty of their vines
with heart-shaped leaves, but no flowers or fruits. Had we found some in
flower, this is what we would have seen.

Funnel Web spider inside the funnel

Funnel Web spiders weave a non-sticky platform of silken threads with a short, cylindrical tube at one edge. The tube serves as a refuge for the spider. When a wandering insect walks across the web the spider detects the vibrations from its footfalls and rushes out from its refuge to grab and bite its victim. The bite injects a venom that paralyzes the insect and begins to digest its internal organs. The spider carries it back to the refuge where it consumes it.

Spider egg case attached to a leaf.

Spider Egg cases are being produced this time of year and they are as diverse in structure and appearance as their makers. In the above photo you can see the tiny spherical eggs in the center of the case. The radiating strands of silk anchor the egg case firmly to the leaf surface. When the leaf drops the eggs will fall to the ground with it.

Bowl and Doily spider web

The Bowl and Doily spider constructs a two-part web: the flat “doily” and a bowl-shaped tangle of silk threads just slightly above. The spider lives in the space between. The silk is not sticky, but the tangle of threads in the bowl makes it difficult for small prey items to walk. In their struggles they alert the spider below and when they reach the bottom of the bowl the spider bites them through the silk. 

A doily, for you youngsters, is a flat, circular piece of lace work that was placed below plates and bowls to protect the surface below from being scratched. 

Redbud Leaffolder caterpillar inside a folded Redbud leaf. The caterpillar is the black and white object inside the fold.

The Redbud Leaffolder is a moth caterpillar that does what its name suggests: it folds a leaf of a Redbud tree. The folding is accomplished by attaching strands of silk produced by glands in the caterpillar’s head to two points on the leaf surface. As the silk dries it shrinks and pulls the two points together, folding the leaf about the caterpillar. It then feeds on the leaf surface inside the fold. Why go to all this trouble? By constructing a hideaway the caterpillar makes it more difficult for predators to find it and for parasitic wasps to attack it.

A Meadow Katydid on White Crownbeard.

Meadow Katydids look like spindly-legged grasshoppers with enormously long antennae. The males produce buzzy calls by rubbing their front wings across one another very rapidly. These calls are attractive to female katydids and each species has its own characteristic call. The part of the wings that is in contact is rough and the scraping of these surfaces produces the sound. If this is a wingless Katydid how can it make sound? It is lacking the hindwings and the forewings are reduced in size. (In the photo the legs block our view of the wings.)

The long antennae separates the Katydid family (Tettigoniidae) from the Grasshopper family (Acrididae). Grasshoppers have very short antennae, no longer than their head is high; in contrast, the Katydid antennae are much longer than their body.

We’re not sure of the identity of this Meadow Katydid. It may be the Short-winged Meadow Katydid (Conocephalus brevipennis) or the Wingless Meadow Katydid (Odontoxiphidium aptera)

Tiger Swallowtail, dark form female on White Crownbeard

Tiger Swallowtail, male on White Crownbeard

SUMMARY OF OBSERVED SPECIES

Red Buckeye	Aesculus pavia
Red Morning Glory	Ipomoea coccinea
Purple flowering mint family	Family Lamiaceae
Smooth (Ohio) Spiderwort	Tradescantia ohiensis
Yellow Crownbeard	Verbesina occidentalis
Ruby Throated Hummingbird	Archilochus colubris
Spiny-backed Orbweaver	Gasteracantha cancriformis
Silver Plume Grass	Saccharum alopecuroides
Sedge	Carex sp.
Purple Fountaingrass	Pennisetum setaceum
Spotted Beebalm, Horsemint	Monarda punctata
Stink Bug	Family Pentatomidae
Sicklepod	Senna obtusifolia
Sleepy Orange (caterpillar)	Eurema nicippe
Praying Mantis	Order Mantodea
Late Flowering Thoroughwort Late Boneset	Eupatorium serotinum
Ailanthus Webworm Moth	Atteva aurea
White Crownbeard	Verbesina virginica
Little Bluestem Grass	Schizachyrium scoparium
Purple Top or Greasy Grass	Tridens flavus
Funnel Web Spider	Family Agelenidae
Bigtop Lovegrass	Eragrostis hirsuta
Flowering Spurge	Euphorbia corollata
Bowl and Doily Spider	Frontinella pyramitela
Woodland Sunflower	Helianthus divaricatus
Ebony Spleenwort	Asplenium platyneuron
Elephant’s Foot	Elephantopus tomentosus
Redbud Leaffolder Moth	Fascista cercerisella
Eastern Redbud	Cercis canadensis
Meadow Katydid	Family Tettigoniidae
Beaked Panicgrass	Panicum anceps
Downy Lobelia	Lobelia puberula
Carolina Milkvine	Matelea carolinensis
Eastern Tiger Swallowtails (male and dark form female)	Papilio glaucus