Leader
for today’s Ramble:
Linda

Authors
of today’s Ramble report: Linda and Don. Comments, edits, and suggestions for the report can
be sent to <Lchafin@uga.edu>.

Link
to Don’s Facebook album for this Ramble. All the photos that appear in this report, unless otherwise
credited, were taken by Don Hunter. Photos may be enlarged by clicking them
with a mouse or tapping on your screen.

Number
of Ramblers today:
22

Today’s
emphasis: Seeking
what we find, in mid-spring, along the Purple and Orange Trails.

Rachel Carson

Reading:

Richard read a quote
by Rachel Carson: “Humankind is challenged, as it has never been challenged
before, to prove its maturity and its mastery, not of nature but of itself.”Don delved a little further into this quote,
curious as to the reading’s origin. He found this article by Maria Popova,
“How
to Save a World: Rachel Carson’s Advice to Posterity,” which places
the quote in the context of Carson’s life:

“In
June 1962, five days before the first installment of Silent Spring made
its debut in The New Yorker, the terminally ill Carson summoned the remnants of
her strength to take her very first cross-country jetliner flight and deliver a
long-awaited commencement address at Scripps College in California… She titled it “Of Man and the Stream of Time” — hers,
after all, was an era when every woman, too, was “man.” It was a
crystallization of Carson’s moral philosophy, a farewell to the world she so
cherished, and her baton-passing of that cherishing to the next generation. She
told graduates:

‘Today our whole earth
has become only another shore from which we look out across the dark ocean of
space, uncertain what we shall find when we sail out among the stars.… The
stream of time moves forward and [hu]mankind moves with it. Your generation
must come to terms with the environment. You must face realities instead of
taking refuge in ignorance and evasion of truth. Yours is a grave and sobering
responsibility, but it is also a shining opportunity. You go out into a world
where [hu]mankind is challenged, as it has never been challenged before, to
prove its maturity and its mastery — not of nature, but of itself. Therein lies
our hope and our destiny.’” Link to
the full text of Carson’s speech.

Show
and Tell:

Richard brought Cross-vine flowers he’d collected in his yard and kept refrigerated for
several weeks. Cross-vine blooms in April, just as Ruby-throated Hummingbirds
arrive in the Piedmont. The four pollen-laden anthers, held at the tips of arching
filaments, and the pistil are all clustered near the mouth of Cross-vine’s
tubular flowers, right where the foreheads of hummingbirds make contact as they
probe for nectar inside the base of the tube. The common name comes not from the
four leaflets at each node, as I long thought, but from the phloem (tissue that conducts sugars from leaves to roots) which forms
an “X,” visible in cross-section, inside the stem.

Stamens clustered at the mouth of a Cross-vine Flower. Photo by David J. Stang

 

Cross-section of Cross-vine stem showing four wedges of phloem forming something like a cross. Photo by Eugene Wofford, courtesy University of Tennessee Herbarium

Linda
brought flowers from a yellow-flowered Wild Indigo to demonstrate how only hefty, large bees can push apart the petals to
provide access to the pollen and nectar. Here is a nice summary of the way bumblebees pollinate bean family flowers.

Announcements/Interesting
Things to Note:

Snake Day is coming Saturday, May 13! Sandy Creek Nature Center, noon to 4:00
pm. Don’t misssss it!

From the Athens C-Change Conversation: “Uncertain
About the Impact of Warming Temperatures? Attend the “C-Change Primer,” a
non-partisan, multimedia presentation about the science and effects of climate
change on Monday, May 15, at Ciné Theater, 234 West Hancock Ave, in Athens. Doors
open at 4:30 for a reception, followed by a presentation and Q&A from 5:00-6:30.
Free and open to the public, with free popcorn. The ‘C-Change Primer’ presents clear, unbiased
information that helps people understand how climate change will impact the
things we all value: jobs and a sound economy, health and personal safety, and
geopolitical stability. It has been widely hailed as an intelligent,
dispassionate introduction to, and illumination of, the topic. The Primer was
developed in conjunction with independent climate scientists and public policy
specialists and has been presented to nearly 17,000 people in 32 states.” 

Saturday, May 20, 2 – 4pm, Georgia nature author, Janisse Ray, will
speak at the Sandy Creek Nature Center in honor of the Nature Center’s 50-year
anniversary. Author of works such as “Ecology of a Cracker Childhood”
and “Wild Spectacle: Seeking Wonders in a World Beyond Humans,”
Janisse is a writer, naturalist, and environmental activist whose deep love of
Georgia shines through on every page. She will speak outside at the picnic
pavilion, so bring a blanket or lawn chairs. Her talk will be followed by a
reception and an opportunity to speak to her and purchase her books.

Today’s
Route:  We left the Children’s Garden and headed across
the Flower Bridge. We passed the China and Asia Section, then passed through
the Threatened and Endangered Plants bed to reach the Purple Trail.  We took it down to the river and headed
across the beaver marsh boardwalk, then turned left onto the Orange Trail,
which we took back to the parking lot.

OBSERVATIONS:

China
and Asia Section:

Voodoo Lily plants in flower

These strange-looking creatures are not lilies – they are in the Arum Family (Araceae) along with  our Jack-in-the-pulpit and has a similar spathe-and-spadix inflorescence that emerges from a tuber. The olive green structure with swollen base and purple-speckled lining is the spathe, the
“pulpit” in Jack-in-the-pulpit. The long, thin, black cylinder rising from the spathe is
the spadix (or Jack) that will eventually produce female flowers at its base,
largely hidden inside the swollen base of the spathe. Male flowers will develop
further up the spadix and mature at a different time from the female flowers to
prevent self-pollination. Large, deeply dissected leaves will appear soon, held at the tip of a fleshy leaf stalk that is mottled pink and olive green. Information on growing this species is here.

Voodoo Lily leaves photographed by Don in June 2018. Each large leaf consists of many leaflets arranged in a horse-shoe shape.

Whitebark Magnolia, a native of Japan with leaves up to 20 inches long, is a “sister species” to our Bigleaf Magnolia.

There are
many such examples of pairs of similar species shared between East Asia and eastern
North America. This phenomenon of closely related but widely separated plant species
has intrigued botanists, including Linnaeus and Darwin, for nearly 200 years, and is
currently believed to be the result of land bridges that existed between eastern
Asia and North America during the Tertiary Period (66 million to 2.6 million
years ago). Click here for
more details.

Threatened
and Endangered (T&E) Plants

Indian Pink is not actually endangered (thank goodness!), but nevertheless lights up the T&E garden every spring. If only it were called “Firecracker Plant”….it is not pink, obviously, and is not in the Pink Family (Caryophyllaceae) either, and the word Indian is always a bit suspicious when applied to plants, often indicating that the namer thought the plant was not the “real thing” they knew from Europe (similar to calling something “false.”

Cooley’s Meadowrue female (pistillate) flowers on the left, male (staminate) flowers on the right. This species is listed as Endangered by both U.S. Fish and Wildlife Service and Georgia’s Department of Natural Resources.

Black Cohosh in bud

Purple
Trail

The trail was littered with newly fallen leaves and twigs, evidence of the high winds we’ve had in the last week.

Among the fallen twigs was this one from a Beech bearing an immature Beech nut (no relation to the chewing gum).

This standing dead tree has supported many birds, small mammals, insects, fungi, and lots more since it died.

Annual quiz: what is the darkest tree in the Garden’s forest?

Christmas Fern produces spores on the uppermost leaflets of its fertile fronds.

Close-up of the spore-producing structures (sori) on the lower surface of a Christmas Fern leaflet

A Basswood leaf, almost but not quite heart-shaped, was found on the path and prompted a search for the tree, never before noted along the Purple Trail –– turns out there were at least two in the vicinity.

The lower leaf surface of our variety of Basswood (var. heterophylla) is densely felted with white hairs. (Photo by Stephen J. Baskauf, Bioimages)

Basswood with many root sprouts Photo by Stephen J. Baskauf, Bioimages

Several ramblers pointed out that the easiest way
to spot a Basswood in the woods is to look for a ring of young stems that
almost invariably sprout from the base of a mature tree. World-traveling ramblers mentioned that European species of Basswood
are known as Linden in Europe and Lime Tree in England and Ireland.

Sourwood leaves look pretty generic – unless you turn them over and run your finger down the line of stiff hairs along the midvein.

 

We heard the songsof Summer Tanagers off and on throughout the ramble–listen here. Photo by T. Cantrell

Hook Moss covered the trunks of many Musclewood trees along both the Purple and Orange Trails

 Orange Trail

The beaver marsh is dominated this time of year by Duck-potato, known to the Cherokee as wapato, an important part of their diet before European colonization. Later in the summer, Rice Cut-grass will overwhelm the marsh.

Duck-potato (above) shares marsh habitat at the Garden and in most of its range with Arrow Arum (below). Although their leaves are similar in shape, they are in different plant families and, while Duck-potato is edible, Arrow Arum is toxic. These photos illustrate the difference in their leaf venation. All of the main veins on Duck-potato leaves originate at the base of the leaf stalk. Most of Arrow Arum leaf veins (below) spread from the central midvein while a separate vein follows the leaf margin. (Click on the photo or tap your screen to enlarge photos.)

Arrow Arum leaf

Duck-potato leaves are covered with a fine coating of hairs. Arrow Arum leaves are hairless but sometimes have a waxy coating. Both are strategies that help protect their leaf surfaces and stomata (breathing pores) from being “swamped.

An iridescent sheen is often seen on the surface of water in marshes and lakes and may appear to be a petroleum-based pollutant.

Karen, the Nature Ramblers’ “in-house” limnologist, explained that the
sheen is a natural phenomena, usually the result of bacteria reacting with naturally occurring
elements. Iron Bacteria derive energy by
converting dissolved iron into insoluble iron, producing iridescent sheens (or
rust-colored slime) as a floating byproduct. The decay of plant material in the
water fosters this process by de-oxygenating the water in marshes and swamps. There
is no evidence that Iron Bacteria films are harmful. To distinguish an
oil-spill film from a bacterial or other natural biofilm, poke the film with a
stick or toss in a rock. If the sheen breaks into separate platelets, it is a
bacterial sheen. If the film quickly reforms around the hole, it is probably a
petroleum sheen.

Thanks to Roger, who has been researching the land use history of the Botanical Garden, we now know that the stream which the Orange Trail follows was named Humphrey’s Spring Branch in an 1826 deed. Evidence of the January storms is still seen all along the branch.

 

Once we crossed the boardwalk and turned left onto this section of the Orange Trail, we began to see Wild Onions in flower.

This is the only native species of Allium
where the flowers share space with bulbils at the top of the stem. In a process
similar to that of Egyptian Walking Onions, Wild Onion bulbils reach the ground
when the stem withers and flops over. If conditions are right, the bulbils will
sprout roots and establish new plants. The shadier the habitat, the greater the
number of bulbils relative to flowers.

You
may be wondering:  bulbils? Bulblets?
Bulbils are produced along with, or in place of, flowers at the top of a stem. Bulblets
are offsets from the underground bulb. Both are forms of asexual reproduction
that produce clones of the parent plant.

Mayapple Rust infects the leaves of many of the Mayapples we saw along the Orange Trail. The upper leaf surface is speckled with yellow or light green (Don’s photo, left), caused by orange spore-producing pustules on the lower surface (photo, right, by Donald C. Drife, The Michigan Nature Guy’s Blog)

Mayapple Rust is a common infection
found only on Mayapples. It appears at about the same time that fruits do and
not long before the plants begin to wither in late spring. It does not seem to affect
the long term health of the population.

Mayapple fruit

Sanicle or Black Snakeroot is not a showy woodland wildflower but like most wildflowers can be pretty dramatic up close. The trick is to have a 10x hand lens.

Broad Beech Fern, officially known to Ramblers as the Fox-head Fern

Myrna captured a small American Toad. These toads are usually brown or gray in color, although some individuals may be olive green, tan, or reddish (as here).There are only two toads in our area, according to Dale, American Toad and Fowler’s Toad, which is distinguished by the presence of three or more warts within dark spots on its back.

 

Fruits of Wild Geranium

Wild Geraniums, abundantly flowering in early April, are now in fruit. Species
in this genus are sometimes called Crane’s Bills or Heron’s Bills because of the long,
pointed shape of the fruit. When the fruits ripen, they split from the bottom into
five sections that curl rapidly upward, hurling their tiny seeds several feet
away. In the lower right corner of Don’s photo, you can see a fruit that has already ejected its seeds.

Solomon’s Plume in flower

Witch Grass flowers with brushy stigmas and oval anthers tipping the stamens

Ramblers consulting the Merlin app to identify the birds whose songs and calls accompanied us along the Orange Trail. According to Merlin, we heard lots of Summer Tanagers, Northern Cardinals, and Tufted Titmice as well as Blackpoll Warblers, Wood Thrushes, Acadian Flycatchers, and several others.

SUMMARY OF OBSERVED
SPECIES:

Crossvine   Bignonia capreolata

Wild Indigo    Baptisa sp.

Voodoo
Lily     Amorphophallus konjac

Whitebark
Magnolia     Magnolia obovata

Indian
Pink     Spigelia marilandica
Cooley’s
Meadowrue     Thalictrum cooleyi

Black
Cohosh     Actaea racemosa

Persimmon    Diospyros virginiana

Christmas
Fern    Polystichum acrostichoides

Basswood   Tilia americana

Sourwood   Oxydendrum arboreum

Chalk
Maple     Acer leucoderme

Mayapple    Podophyllum peltatum
Mayapple
Rust     Puccinia podophylli,
synonym Allodus podophylli
Wild
Onion     Allium canadense

Musclewood    Carpinus caroliniana

Hook
Moss     Leucodon sp.

Sensitive
Fern     Onoclea sensibilis

Duck Potato, Wapato  Sagittaria latifolia

Arrow
Arum     Peltranda virginica

Jack-in-the-Pulpit    Arisaema triphyllum

Lion’s Foot     Prenanthes serpentaria, synonym Nabalus serpentaria

Sanicle, Black Snakeroot     Sanicula canadensis

Round-lobed
Hepatica     Anemone americana

Broad Beech
Fern     Phegopteris hexagonoptera

Upright
Carrionflower     Smilax ecirrhata

Heartleaf
Ginger     Hexastylis arifolia

American Toad     Bufo [Anaxyrus] americanus

Solomon’s Plume  Baeolophus bicolor

Witch
grass     Dichanthelium sp.

Tufted
Titmouse   Baeolophus bicolor 

Northern Cardinal  Cardinalis cardinalis

Blackpoll Warbler        Setophaga striata 

Wood Thrush        Hylocichla mustelina

Acadian Flycatcher  Empidonax virescens