Today’s report
was written by Dale Hoyt. The photos that appear in this blog are taken by Don
Hunter; you can see all the photos Don took of today’s Ramble
here.

Twenty-five ramblers met at the Arbor at 8:30AM on a fine
morning.

Today’s reading:
Avis read an excerpt from Janisse Ray’s Drifting
into Darien, pp 163-164:

I’m
going to give you some advice right away about botanists.  Never go out in the woods with them. Never go
anywhere. If you do, you’ll never get to where you’re going.  They want to stop every few feet to bend down
and look at something.  They carry little
magnifying glasses with them so they can count parts of flowers so small they’d
get lost in a thimble.  The botanists are
shamelessly looking to see if leaves are hairy or smooth, if they have glands,
how their veins run.  You have to keep
your body covered when you’re with botanists. 

So
it’s mid-October, a day that would win a beauty pageant it is so fine, a
perfect day, and I’m standing at a granite-and-stone marker erected by the
National Park Service in 1976 that proclaims this scrubby little hill a
Registered National Landmark.  And I’m
with a group of people who have their pants tucked in their socks and who are
crawling around in the grass with magnifying glasses.  They are examining the grasses, in fact, and
speaking a language I don’t understand while doing so.

“I
think these are Aristida purpurascens.”

“Well,
it could be three-awn grass.  Looks like
wiregrass but isn’t.”

“Oh,
here’s a little bluestem,” someone calls. 
“Related to Andropogon.”

Come
on, people, you’re embarrassing me. 
Somebody’s gonna pass on the road and see me out here with you all,
crawling around in the dirt.  I live in
this county, remember?  Also, I want to
see what’s at the top of this little mountain, so we’ve got to pep it up a
little.

“We’ve
got Vitus rotundifolia all over the
place.”

“Here’s
Smilax pumila.”

What,
have we been invaded?  This sounds a lot
like Star Wars to me.

A
few feet ahead is a flower in bloom. 
Don’t give these people a flower. 
They go crazy.

Today’s route: We
walked to the bottom of the Dunson Garden and from there took the power line
right of way to the river. At the river we turned left on the Orange trail and
the left on the Orange trail spur back to the parking lot.

Today’s challenge:
Learn to identify the three species of wingstems and determine any other ways
in which they differ. Observe where these species are found in the power line
and what their relative abundance in each area is. Formulate ideas or guesses
about what would explain any difference in occurrence in each part of the power
line.

Dunson Native Flora
Garden: Our primary reason for stopping at the end of the Dunson Garden was
to examine two of the three wingstem species that are found in the power line
right of way. The three wingstems can be distinguished from one another by a
combination of two features: 1) the arrangement of the leaves and 2) the color
of the flowers, as shown in this table:

				Flower color
				Yellow	White
Leaf arrangement		Alternate		Wingstem Verbesina alternifolia	White crownbeard Verbesina virginica
		Opposite		Yellow crownbeard Verbesina occidentalis

But there are other ways in which these plants differ and
one of our goals today was to discover those other characteristics. To help you see how much you learned today here is a little quiz (answers at the bottom of this post):

#1 — Which wingstem is on the left? On the right?

#2 — Which Verbesina is this?

#3 — Which Verbesina is this?

#4 — Which Verbesina is this?

This is the time of year when we often find caterpillars.
It is late enough in the season that

Virginian Tiger Moth caterpillar

they have grown large enough to be conspicuous.
We found a very hairy/fuzzy caterpillar prominently perched in plain sight on a
tall plant. Jeff and I both thought that it was in the Tiger moth family and
that turned out to be correct. On returning home I looked for it in my go to
reference for caterpillars: Caterpillars
of Eastern North America, by David L. Wagner. There it was on page 465: the
Yellow Bear (AKA Virginian Tiger Moth), Spilosoma
virginica. But, I hear you say, I saw that caterpillar and it wasn’t
yellow, it was reddish brown. Well it turns out that the caterpillars of this
species are very variable in coloration – the young ones are light in color but
they darken as they age, like tow-haired children getting darker hair in
adulthood. The adult moths are very pretty: all white wings and abdomen except
for a row of black dots and orange patches on the side of the abdomen. Look for
them at your porch light; maybe you’ll be lucky.

At the very bottom of the garden we found Late flowering
thoroughwort and Silver plume grass. The latter has leaves that resemble those
of an invasive pest species: Johnson grass. When these two grasses are not
flowering they appear almost identical – the leaves are broad and have a
prominent white mid-vein. So if they are not flowering be careful what you pull
up. When the two grasses are flowering they are quite distinct. Silver plume
grass has a seed head that resembles the imported Pampas grass (in fact, it
would be a wonderful native replacement for that plant).

At the power line
right of way we wandered about, stunned and delighted by the height and
density of all the wingstems (Verbesina sp.), to say nothing of the other plants growing among
them.

This area, between the Dunson Garden and the river, is mostly
dominated by the Verbesina, but there are other fall flowering plants growing
here:

Hover fly

We found the caterpillar of the Gulf Fritillary, several bees
and a hover fly. Hover flies resemble bees in color and pattern but they are
harmless. The adults visit flowers and feed on pollen. Their young are
predators, feeding on aphids. How do you distinguish them from bees? First, by
their behavior. True to their name they can hover; staying absolutely
motionless in flight, except for their wings that are just a blur. Being true
flies, they only have a single pair of wings, the other pair being reduced to
tiny knobs, like miniaturized lollipops. Lastly, they have stubby antennae,
unlike the thread-like antennae of bees.

The caterpillar of the Gulf Fritillary is gaudy, with
orange and purple stripes that run the

Gulf Fritillary caterpillar

length of its body. They are easy to
find on their host plant, the passion flower (AKA Maypop). Why are they so
conspicuous? Usually when you find an insect that stands out or is gaudy it is
protected by some attribute. It can be distasteful, harmful (it can sting), or poisonous
if eaten. Or, it can be harmless and just resemble an insect that isn’t. The
latter case is called mimicry. So which is the Gulf Fritillary caterpillar? It
is distasteful or perhaps poisonous. The leaves of maypop contain several types
of toxic substances. In feeding on them the caterpillar acquires these poisonous
compounds and they are transferred to the adult butterfly, making both the
caterpillar and the adult undesirable as a meal for hungry birds.

Goldenrod spherical gall

Another insect was detected by its gall: the goldenrod gall
fly (Eurosta solidaginis). Photos and
details of the life history can be found here.
In the spring the flies emerge from the galls, mate and lay their eggs on the
growing tip of goldenrod plants. The maggot secretes chemicals that stimulate
the plant to form the gall: a spherical swelling with a hard outer shell. The
maggot feeds on the tissue inside this gall.

Spherical gall fly maggot

As the time approaches to pupate
the larva excavates a tunnel to the outer part of the gall, but leaves a “window,”
the thin skin of the outer covering. When the fly emerges from the pupa it
crawls up the tunnel and pops open the window with a balloon-like swelling on
its head. Don found another gall and split it open; the maggot was still inside
and we passed it around for all to see.

“Beggar’s ticks” (seedpods of tick trefoil)

Naked-flowered tick trefoil was seen, or rather, its fruits
were seen. This plant in the bean/pea family has a pretty little flower in
spring and spends the remainder of the summer producing its seed. Like other
members of the bean/pea family it produces pods that contain a long row of
seeds. But these pods are not your ordinary pea pods. They are flattened and covered
with tiny, velcro-like hairs that adhere to the clothing of the unsuspecting passerby.
Most people know them as beggar’s ticks or beggar’s lice.

Golden aster

At the sunnier edges of the path we found a Golden aster (Heterotheca latifolia) in bloom
alongside Hairy sunflower, Dog fennel and Late flowering thoroughwort. Growing
among the

Hairy sunflower

various wingstems and almost obscured by them are American pokeweed
and Fireweed. Among the wingstems we found a single Field thistle with flowers
that look a little tired, as if they know that fall is approaching. The wild
senna that we have seen in bloom earlier this summer has set seed and one plant still has a
single yellow blossom. The Golden aster we find in this part of the power line
has another common name: Camphorweed. Unfortunately, another plant (Pluchea camphorata) that we also find in
the power line has the same common name. The Pluchea leaves have a much
stronger odor than the Golden aster leaves do.

As we get closer to the river the Goldenrod seems to
become more abundant. Goldenrod gets blamed for causing Hay Fever this time of
year. It is innocent. Most of the plants that have showy flowers in the fall
are insect pollinated, that’s what those flowers are for – attracting pollinators.
The pollen grains of these plants are sticky and heavy; they are designed to
stick to insects, not be blown about in the wind. It is the plants that are
wind pollinated that produce the pollen that Hay Fever sufferers are allergic
to. They just happen to bloom at the same time as Goldenrod. Remember: correlation
is not causation.

Many of the Goldenrod have multiple, small flowering
shoots whereas others have a single main flowering shoot. The plants with
multiple flowering shoots don’t have as many flowers and generally don’t seem
as healthy. If you look carefully at them you can see that the multiple shoots
arise from the end of a stem that was cut off earlier in the season. When the
growing tip of a plant is removed lateral buds below the cut begin to grow and
the energy that would have gone to the single shoot now is divided among the
new crop of growing buds. Thus each new shoot has a smaller share of the available
energy to produce flowers. Who cut the top out of the Goldenrod? A four legged
vandal known as the White-tailed deer.

At the fence post of the old electrified anti-deer fence
we found a single blossom of the Red morning glory. This plant has been
climbing up this fence post for as long as the rambles have been going. Jennie
inquired about the scientific name and this set off a round of “toe-may-toe,
toe-mah-toe” when I said “It’s Ipomoea
coccinea” (pronounced: Ip-o-ME-ah). Jennie responded with “Do you
mean ‘eh-POM-e-ah’?” Then Avis waded in with a verse from “The Girl
from Ipanema.” I still don’t know which is the correct pronunciation, but now we’ll surely remember the generic name for morning glories.

How do you
pronounce scientific names? The
first method is imitation. Most people, scientists included, learn the
pronunciation of scientific names by hearing someone else, usually a teacher or
professor say them. There are, however, some general guidelines to help you
learn how to pronounce them. First, break the word into syllables. As a rule of
thumb, every syllable will have at least one vowel. But this is not so easy.
One reason computer synthesized speech sounds so artificial and sometimes just
plain wrong is that it is very difficult to design an algorithm to recognize
syllables correctly. Using our Ipomoea example, the syllables could be: “I/po/moe/a”
or “I/pom/oe/a” or “Ip/o/moe/a”. So you could pronounce it:
“eye-poe-mow-ee-ah”, “eye-POM-oh-ee-ah”, or “Ip-oh-ME-ah”.
The last three letters are tricky, so this isn’t a great example. The “oe”
vowel combination could be pronounced as if it is just a long “e”, or
you could separate them as “o/ea”, pronounced “oh-eeuh”.
Confusing? Yes. So just give it your best try and if it sounds reasonable it’s
probably OK. One other guide line – which syllable do you stress? Many people
think that the antepenultimate syllable should be stressed. (Antepenultimate
means third from the end.) Example: The genus name for Evening primrose is
Oenothera. I’ve heard it pronounced two ways: “ee-no-THee-ra” and
“ee-NOTH-er-ah”. Maybe both ways are “correct.” So just try your best to pronounce an unfamiliar
name. No one should make fun of your pronunciation. If they do, it reflects
more on them than it does on you.

British soldiers lichen on a fence post

That old fence post revealed more secrets than idiosyncratic
pronunciations. Hiding on a tiny ledge was a lichen garden featuring British
soldiers lichens. They must have been attracted to the Red morning glory. At
the foot of the post was a solitary Bitterweed, still in bloom, a plant that we
usually see higher up the hill.

Climbing false buckwheat

Arrowleaf tear-thumb

We found several different vines climbing over and in
the masses of goldenrod and Verbesina:
Arrow-leaf tear-thumb (a plant not previously seen in the garden), Climbing
hempweed, Small white morning glory, Climbing false buckwheat and Trailing wild
bean. The tear-thumb is aptly named because its stems are covered with tiny
thorns all pointed in the same direction. You can pinch the stem between thumb
and finger and slide them in one direction and you will only feel a little
roughness. Slide them in the opposite direction and the result is as the name
implies.

Virginia dayflower (Note the three pale blue petals)

Other plants that were observed in this section of the
power line: Pennsylvania smartweed, Leafy elephant’s foot, Mild water pepper, Tall
ironweed, Camphorweed (Pluchea camphorata) and Virginia
dayflower. The Virginia dayflower is a native species that is very similar to
the widespread introduced weed, Asiatic dayflower. They both have flowers that
are open for only a single day, hence the name. The Asiatic dayflower has two
large, dark blue petals arranged like Mickey Mouse ears. Similarly, the Virginia
dayflower the two large, pale blue petals plus a much smaller pale blue petal located where
the two larger ones meet.

Turning left at the river we made our way along the
Orange trail where last year Thomas Peters single-handedly removed the privet
that once covered the area. We have wondered what will come up in the open
areas created by his work. The privet had covered much of the flood plain so
densely that little or no sunlight could penetrate and for so many years that
it is highly unlikely that many plant seeds could have remained in the soil. It
is more likely that wind and bird dispersed seeds would make their way into the
newly cleared areas.

Silvery checkerspot caterpillar

Almost immediately after turning onto the Orange trail
someone spotted a Silvery checkerspot caterpillar on a well-chewed Wingstem. We
have seen the adults of this species each time we visited the power line this
summer and the abundance of the Wingstem suggests why this checkerspot was so
frequently encounted.

Bur cucumber flowers

Bur cucumber fruits (plus unknown caterpillar)

Bur cucumber is very abundant both to the right and the
left of the trail and the plants are flowering now. Some have developing fruits
and you can see where the species gets its common name. The cucumbers are never
as large as the commercial one you find in stores – they are a different
species.

Fireweed seeds ready to disperse on the wind

There are many Fireweed plants growing in the privet-vacated
areas. Their downy tufts of wind dispersed seeds make it easy to see how this
species would be one of the first to colonize the area.

Camphorweed (Pluchea camphorata)

Other plants we have seen growing along the Orange trail are the
Camphorweed, Blue mist, Climbing hydrangea and Cat brier.

Today’s reading was prescient. It took us much longer to
finish this short section of the trail and return to Donderos’ for our
customary conversation and food.

SUMMARY OF OBSERVED SPECIES:

Obedient plant	Physostegia virginiana
White crownbeard	Verbesina virginica
Yellow crownbeard	Verbesina occidentalis
Carpenter bee	Xylocopa virginica
Tiger moth caterpillar	Arctidae
Late flowering thoroughwort	Eupatorium serotinum
Silver plumegrass	Saccharum alopecuroides
Pennsylvania smartweed	Polygonum pensylvanicum
Leafy elephant’s foot	Elephantopus carolinianus
Wingstem	Verbesina alternifolia
Field thistle	Cirsium discolor
Goldenrod	Solidago sp.
Fireweed	Erechtites hieracifolius
American pokeweed	Phytolacca americana
Naked tick trefoil	Hylodesmum nudiflorum
Golden aster	Heterotheca  latifolia
Dog fennel	Eupatorium capillifolium
Hairy sunflower	Helianthus hirsutus
Mulberry	Morus sp.
Mild water pepper	Polygonum hydropiperoides
Red morning glory	Ipomoea coccinea
Bitterweed	Helenium amarum
British solder lichen	Cladonia cristatella
Tall ironweed	Vernonia gigantea
Gulf fritillary caterpillar	Agraulis vanillae
Wild senna	Senna marilandica
Camphorweed	Pluchea camphorata
Ailanthus web worm moth	Atteva aurea
Arrow-leaf tearthumb	Persicaria sagittata
Virginia dayflower	Commelina virginica
Goldenrod gall fly maggot	Eurosta solidagini
Climbing hempweed	Mikania scandens
Small white morning glory	Ipomoea lacunosa
Hover fly	Family Syrphidae
Honey bee	Apis mellifera
Climbing false buckwheat	Fallopia scandens
Trailing wild bean	Strophostyles helvola
Wood nettle	Laportea canadensis
Silvery checkerspot	Chlosyne nycteis
Bur cucumber	Sicyos anqulatus
Blue mist flower	Conoclinium coelestinum
Climbing hydrangea	Decumaria barbara
Catbrier	Smilax bona-nox

Answers to the quiz:

#1: V. occidentalis on the left; V. alternafolia on the right

#2: V. alternafolia; Wingstem

#3: V. occidentalis; Yellow crownbeard

#4: V. virginica; White crownbeard