Sunday, September 20, 2015

Ramble Report September 17 2015



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






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