Today's Ramble was led by Dale Hoyt.
Here's the link
to Don's Facebook album for today's Ramble. (All the photos in this post are
compliments of Don, unless otherwise credited.)
Today's post was written by Dale Hoyt.
Today’s Focus:
32 Ramblers met today.
Today's reading:
Today’s non-inspirational, fact-filled reading about Witch Hazel was from
Donald Culross Peattie’s A Natural History of Trees of Eastern and Central
North America. (If you are at all interested in trees, this is a book you
should own.)
[Witch Hazel] fruits are stranger still, for
those of last year are just ripening at the time that this year's flowers appear.
More, they eject
their shiny, hard, black seeds with violence; the tree, which seldom grows
more than 20 feet
high, can send
its seeds much farther. Reliable observers, who have kept the pods in the house and could measure the distance of the ejection precisely,
report 25 and 30 feet. The viability of these little missiles is high, and thus the wintry-blooming Witch Hazel,
of ancient geologic
lineage, is still today well able to
maintain
itself.
. . .
Witch Hazel is usually said to have its name
from a confusion
in the minds of the early settlers between this plant and the true Hazel, and
there is some resemblance between the leaves and the appearance of the young fruits in the two species. The Hazel of Europe was famous for its magical properties; some legends say that one can
find witches by means of it, and others that with its help witches
can find water, or gold, or other desirable
subterranean things. Philologists like to dispute
this source of the name, saying that it comes from the word wych which has nothing to do with witches but is related, according to various and sundry authorities, to Anglo-Saxon wicken, meaning to bend, or Old English wick, meaning quick or living, or possibly even to the modern word, switch.
However
all that may be, it is certain that, in early days in America, Witch Hazel was
used in local witchery, to find water or even mineral deposits. You took a forked branch, one whose points grew north and south so that they had felt the influence
of the sun at its rising and setting, and you carried it with a point in each hand, the stem pointing forward. Any downward
tug of the stem was caused by the flow of hidden
water or the gleam of buried gold. And if there are
people still who believe
in water-witching, theirs is one of the most harmless
and pleasing of fallacies.
Today's route:
From the plaza past the Children’s Garden and the old Arbor to the sidewalk
through the upper Shade Garden and out on the access road. Down the road to the
Passionvines, then briefly into the lower Dunson Garden and out to the Power
Line. We rambled the power line ROW, some of us reaching the river, then
returned to the Visitor’s Center.
Observations
Southern Magnolia floral visitors. Some
ramblers spotted a lot of insect activity in one of the large flowers of a
Southern Magnolia. Karen had the presence of mind to make this
video of the bees gathering pollen. The stamens in Southern Magnolias are
not well differentiated into filaments and anthers. The red-tipped “sticks” you
see in the video are the stamens of the Magnolia flower. Unlike most flowering
plants, the stamens are not well differentiated into filament and anthers. The
red tip of the short white stamen is the anther end. In the video the bees are
frantically scraping the pollen from the anthers and, in doing so, removing the
stamens from their point of attachment. Some of the bees can be seen carrying
masses of pollen on their hind legs.
Magnolias appeared early in the fossil record of flowering plants, so early, in fact, that there were no bees present at the time. It was thought that the pollinators of Magnolias must have been beetles. Clearly the bees have not read the books.
Magnolias appeared early in the fossil record of flowering plants, so early, in fact, that there were no bees present at the time. It was thought that the pollinators of Magnolias must have been beetles. Clearly the bees have not read the books.
American Witch Hazel always makes us wonder how it
got its name. On an earlier ramble Catherine read a passage from Mary Durant's Who
Named the Daisy? Who Named the Rose?, p. 210, 1976, Dodd, Mead & Co.,
that explained it all. (You might be interested in comparing Donald Culross
Peattie’s derivation of the name from today’s reading.):
“WITCH HAZEL has nothing
whatsoever to do with witches, despite the plant's mystic knack as a divining
rod for water and precious ores. The old name is quite prosaic, no magical
spells here. Witch comes from wych, a
variant of the Anglo-Saxon wican, to
bend. (This is also the root word for wicker, which is woven from bendable or
pliable branches.)
The name witch-hazel was given
to the shrub because the leaves resembled those of the English elm tree with
long, drooping branches that was known as the wych-elm; that is, "the
bending elm." And the wych-elm was also called wych-hazel, because its leaves
resembled those of the hazel tree. (The origins of elm and hazel, both Old
English, are uncertain.) Over the years, "wych" was transformed into
"witch." (The other kind of witch comes from the early English wicca, a wizard.)
 |
| A Witch Hazel leaf with a conical gall. Inside the gall are 50+ aphids, all descended from a single female foundress. (click to enlarge) |
Today we saw cone-shaped galls on the Witch Hazel leaves.
(A gall is an abnormal growth of plant tissue. They have a variety of causes:
injury, insects of various kinds feeding on the plant, fungal and bacterial
infections. Many of the insect-caused galls are highly species-specific in
shape. The cause of this specificity remains a mystery.)
The galls form when the witch-hazel cone gall aphid (Hormaphis
hamamelidis) crawls into the leaf bud in the spring. As the leaf grows, the
aphid injects a substance, possibly an enzyme or hormone into the leaf tissue,
which causes the gall to form around her. She produces 50 – 70 offspring,
beginning four cycles of reproduction on the host tree, allowing the aphid to
increase its population dramatically in a relatively short period of time.
Reproduction is parthenogenetic, meaning the female can produce offspring
without any male contribution. The aphids have not completely abandoned sexual
reproduction, however. At certain times of the year they produce winged males
and females (parthenogenetically!) that mate and the females fly to an alternate
host plant, a Birch tree. There they lay eggs that overwinter and, in the
spring, the young aphids again produce a winged generation that flies to the
Witch Hazel to begin the cycle again.
The American witch hazel is almost unique in flowering in
the late fall into winter, with yellow flowers that have four twisted,
ribbon-like petals. Other plants are becoming dormant at this time. The flowers
are pollinated, possibly by winter moths that are adapted to flying in cold
weather. The fruits take most of the year to develop and finally ripen the
following autumn. As the seed capsule dries it places the seeds under pressure
and eventually they are explosively ejected considerable distances.
 |
| A
pecan/hickory weevil with elongated snout. (photo courtesy of Katherine Edison) (click to enlarge) |
Hickory/Acorn Weevils lay their eggs on the developing
fruits of their host trees. The long snout of the weevil, long even by weevil
standards, has a pair of mandibles at its very end. With these the weevil can
chew its way through any thick or thin husks that cover the developing nut and
then lay an egg in the hole. When the egg hatches the weevil grub starts
feeding on the nutritional tissue intended for the embryonic plant. As fall
approaches the weevil achieves its full growth and is ready to leave the host
nut.
 | |
| Hickory nut with weevil larva exit hole. (photo by Angeli Menon, 10/27/2016) (click to enlarge) |
After the nut falls the grub chews it way through the hard nut shell and,
in the case of hickory nuts, through the husk that covers the nut. Wiggling
through the hole it just made it falls to earth and buries itself in the leaf
litter and soil where it pupates. The following spring the adult weevils will
emerge just in time for their host plants to be flowering.
|
But that’s not the end of the story. The grub has left
behind a partially eaten oak or hickory nut with some empty space. Apartment
for rent!
There are certain species of ants, Temnothorax sp., that seek
out and colonize the empty space in the acorn/hickory nuts. They make a snug
home for the queen and her 100 or so workers and brood, all protected from the
weather. In nature there seems to be a use for everything.
|
| Look carefully at this photo again -- sitting on top of the hickory nut you will see a tiny Temnothorax sp. ant! (photo by Angeli Menon, 10/27/2016) (click to enlarge) |
 |
| Notice the very long 2nd pair of legs of the Daddy Longlegs harvestman. They are used as a substitute pair of antennae. (click to enlarge) |
Daddy Longlegs (also known as Harvestmen) are a
type of arachnid. (The formal name for the group is Opiliones.) The number of
legs is a useful character in distinguishing the major groups of Arthropods:
Arthropod Group
|
No. of pairs of legs
|
No. pairs of legs per
body segment |
Insects
|
3
|
1
|
Arachnids
|
4
|
1
|
Crustaceans
|
>4, <Many
|
1
|
Centipedes
|
Many
|
1
|
Millipedes
|
A whole lot
|
2
|
Harvestmen legs are extraordinarily long and spindly. The
second pair of legs are the longest and spindliest. When they walk, they hold
these legs in front of them and constantly sweep them back and forth, using
them as substitute antennae, which all arachnids lack.
A perpetual urban myth is that Daddy Longlegs are
terribly venomous, but have tiny jaws and can’t bite through human skin. In
fact, they have no venom glands, so the legend is only half true. They eat
mostly dead, decaying things and are entirely harmless to humans.
(Note on the difference between venomous and poisonous:
When something you
eat kills or sickens you, it was poisonous. When something bites or stings you
and you die, or get sick, it was venomous.)
 |
| Structure of a Purple Passionflower from the top down: three stigmas atop three styles, the ovary, two of five anthers. (photo by D.L.Hoyt) (click to enlarge) |
Purple Passionflowers have an unusual structure.
A vertical post rises from the middle of the blossom,
above the petals. About ¼ inch above the bottom of this post there is a circle
of stamens with their anthers held horizontally, parallel to the floral disk.
The distance between the anthers and the base of the flower, where the nectar
is, is just right for large bee, like a Carpenter Bee, to contact the anthers
when it visits to flower for nectar. On the other hand, a honeybee visiting the
flower is too small to touch the anthers while getting nectar.
Above the circle of anthers the post is slightly swollen.
This swelling is the ovary, where the ovules that will develop into seeds are
found. Above the ovary the post splits into three parts, the styles, each
ending in a swelling – this swelling is a stigma, the location where pollen
must be placed to produce seeds.
When the flowers open in the morning the three styles are
initially pointing upwards. In some flowers they remain in that position,
whereas in others they soon bend downwards until their stigmas are at the same
level as the anthers, in position to receive pollen.
This
video shows a Carpenter Bee getting nectar from a flower with flexed
styles. Notice two things: 1) the bee is just the right size to brush its
thorax against the anthers as it moves around the flower looking for nectar and
2) the stigmas are at the level of the anthers so, as the bee moves about the flower, its thorax also
comes in contact with the stigmas. When that contact happens pollen grains are
transferred from the bee’s thorax to the sticky stigma.
(Review of flowering plant reproduction, for those who
don’t remember: A pollen grain contains a single sperm. To deliver this
sperm to an ovule in the ovary the pollen grain must first be placed on the
stigma of the flower. There the pollen germinates and begins to grow a pollen
tube. The tube grows through the style into the ovary, carrying the sperm cell
with it. When the pollen tube reaches an ovule within the ovary it releases the
sperm cell which then fertilizes the egg cell within the ovule.
Note: The summary above just focuses on the formation of the plant embryo. The actual process of making a seed is more complicated, involving a process called "double fertilization." I'll explain that at a future date.)
Note: The summary above just focuses on the formation of the plant embryo. The actual process of making a seed is more complicated, involving a process called "double fertilization." I'll explain that at a future date.)
Flowers with unflexed styles will not be fertilized
because their stigmas are too far away from the activity of the bees foraging
for nectar. Because of this they are functionally male, because they can produce pollen
and transmit it to Carpenter bees, but cannot develop fruits and seeds. Thus, there are two types of Passion flowers:
hermaphroditic flowers that can produce seeds and pollen, and male flowers the can produce pollen only.
 |
| Bisexual Purple Passionflower with flexed styles and Carpenter Bee foraging for nectar. (photo by D.L.Hoyt) (click to enlarge) |
 |
| A male Purple Passionflower with unflexed styles and a Carpenter Bee foraging for nectar. The stigmas are too far from the bee to receive pollen so the flower will not produce a fruit or seeds. (photo by D.L.Hoyt) (click to enlarge) |
Why should a passion vine produce male-only flowers? The flowers last only one day, so the energy required to make the flower is the same, no matter whether it is male or bisexual. The additional cost comes when the bisexual flower has been pollinated. Then it starts to form a fruit with a lot of seeds, a process that will take a month or more. Each fruit is a drain on the plants available energy; more fruits developing, less energy available to each one. If this idea is correct, you would expect passion flower plants to produce more male flower as the season progresses.
To test this idea University of Florida researchers counted the number of
each kind of flower in a patch of passion flowers over one growing season of 13
weeks. In the first week bisexual flowers outnumbered the male flowers by 25%, as expected. In subsequent weeks the proportion of male flowers
began to increase. At week 6 there
were twice as many male as female flowers and in weeks 9 and 10 male flowers
outnumbered females 5 to 1. The growing season ended with male flowers twice as
frequent as females.
The researchers also conducted a more direct test of
their hypothesis by manipulating fruit production. Each day, after recording its sexual
status, they
clipped off the ovary of every flower that opened. These
ovariectomized plants not only produced more flowers compared to the unclipped
control plants (704 vs. 351), but they produced almost twice as many
hermaphroditic flowers (63% vs. 36%). This is strong support for idea that the
plants can manipulate the sex ratio of their flowers to adjust the number of
fruits to the amount of resources available.
But why not just stop making flowers? That would leave
all of the plants energy to the developing fruits. A plant has two ways of passing
on its genes to the next generation: producing seeds and producing pollen.
Making a flower is cheap compared to making a fruit. By making a male flower
the plant continues passing its genes on via the pollen, thus increasing its
chances of contributing some of its genes to the next generation. That’s what
evolution is all about.
 |
| Carolina Grasshopper held by the wing tips. (click to enlarge) |
The Carolina grasshopper is difficult to spot when
it is simply standing still on bare soil. Its body is well camouflaged with a
mixture of light and dark brown areas. If it sits motionless, it blends in with
its background so perfectly that it is almost impossible to notice.
But when it
is disturbed it leaps into the air, propelled by powerful hind legs, and flies
away, displaying beautiful black and yellow wings. After flying 10-15 yards it
suddenly folds its wings and lands, disappearing from sight again. It's a
clever trick. The eye follows the prominently colored wings and continues to
look for them in the direction of flight, even after the insect has dropped out
of sight.
 |
| Carolina Grasshopper hind wing expanded and held by the wing tip. (click to enlarge) |
This is a behavior pattern seen in other animals that are
prey for visually hunting predators – become noticeable as you dash away and
then suddenly become less noticeable, apparently disappearing. You may have
seen cottontail rabbits perform this trick with their short tail that is white
beneath and gray above. When startled the rabbit leaps away, raising its tail,
showing the conspicuous white underside. The rabbit dashes away, hopping
erratically and then, suddenly, it lowers the tail and freezes, apparently
disappearing: hop, hop, hop, . . ., “vanish.”
 |
| Carolina Grasshopper's strap-like front wing. (click to enlarge) |
Many kinds of insects have two pairs of wings. In
grasshoppers the first pair of wings are straight and strap-like; the second
pair are shaped like a fan. It is the colorful hind wings that supply the power for
flying; the front wings cover the hind wings and contribute to the camouflage of the
grasshopper when it is on the ground.
A little bit about Insect classification. Insects
are divided into smaller groups called "Orders" that share a
common set of features, the structure of the wings being an important feature
that differs between Orders. Grasshoppers are members of the Order Orthoptera
(pronounced "or-THOP-ter-ah"), which means "straight wing"
and refers to the shape of first pair of wings. (The prefix ortho- means
straight and the suffix –ptera means wing.) The names of many Insect
Orders end in –ptera and the prefix refers to the different ways the
wings are modified. For example, butterflies and moths are in the Order
Lepidoptera (pronounced "lep-uh-DOP-ter-ah." Lepido- means scale and
refers to the colored scales that cover the wings of moths and butterflies like
shingles cover a roof.
Within the level of Order insects are grouped into Families. In the animal kingdom all the family names end in "idae." For example, Grasshoppers are in the family Acrididae (pronounced
"a-CRID-uh-dee," and Katydids are in the family Tettigoniidae (pronounced
"tet-uh-go-NIGH-uh-dee.") Sometimes it's easier to just use the
common names, but these order and family names are universal, whereas the
common names for the groups differ depending on the language being spoken. In
Spanish the name for butterfly is mariposa; in German it is Schmetterling. But
no matter what country you're in Lepidoptera would be recognized as referring
to butterflies and moths.
 |
| Junior Ramblers Nathan and James If only we had their eyesight! (click to enlarge) |
Our two junior Ramblers, Nathan and James, were very
helpful today, finding and catching most of the insects we observed.
 |
| Adult Leaf-footed bug A nymph is above the adult and to the right. (click to enlarge) |
 |
| A group of Leaf-footed bug nymphs on the Yucca flower stalk, just below the adult in the photo above. (click to enlarge) |
Emily made a short video of an aggregation of adult bugs on the same Yucca a few days earlier: Leaf-footed bug video. You can see them using their "leaf foot" for what I think might be an aggressive signal -- a sign to "keep your distance," perhaps.
The nymphs have brilliant red bodies and black legs,
which usually is associated with noxious or toxic qualities. The adults lack
the color but have a scent gland that emits an unpleasant odor when they are
picked up, but the adults lack the red color. I’m looking for a volunteer to do
a smell test to see if they are mimicking something distasteful or not.
 |
| A Long-horned beetle, Family Cerambycidae, possibly Astyleiopus variegatus (??). (click to enlarge) |
 |
| Pearl Crescent butterfly (click to enlarge) |
 |
| Silvery Checkerspot butterfly (not seen today) (click to enlarge) |
The Pearl Crescent is a common butterfly that is often confused with the Silvery Checkerspot. The checkerspot is larger and its larval host plants are wingstems. The larval host for the Pearl Crescent is various asters. Maybe you can tell the difference if you compare these two photos. Give up? Look at the row of black dots on the hind wings. The checkerspot will have one or more dots with an orange center, making a black circle. None of the dots on the Pearl Crescent has a lighter center. There are other differences, but they are difficult to describe.
 |
| A pair of Sleepy Orange butterflies in copulo; female is on the left (click to enlarge) |
 |
| Maryland Senna has compound leaves; the terminal leaflets are paired. (click to enlarge) |
 |
| Extra-floral nectary on Maryland Senna leaf petiole. It's the dark bump just below the leaf. (click to enlarge) |
Senna is one of the plants that has extra-floral
nectaries. You can find them on the leaf petioles, a little way from the point
of attachment to the stem. It’s a small, dark bump that secretes nectar. The
EFN attracts ants and, in the course, of looking for it, the ant crawls all
over the plant. When it finds something else that it could eat, it does. That
something else could be almost anything edible: the egg of another insect or
the small larva of a butterfly or moth. Larger caterpillars could probably
escape, but they would be discouraged from feeding on the plant by the presence
of ants. In effect, the ants have become bodyguards paid by the plant with a
small amount of sugar solution.
 |
| An Assassin bug nymph. The head is to the right and the piercing, sucking beak is folded under the head, pointing backward. (click to enlarge) |
Assassin bugs can also administer a painful bite to
people if handled carelessly, but they don’t inject enough dissolve a human
being.
 |
| Velvet Ant; a female solitary wasp, not an ant. (click to enlarge) |
SUMMARY OF OBSERVED SPECIES
Southern Magnolia
|
Magnolia grandiflora
|
American Witch Hazel
|
Hamamelis virginiana
|
Red Hickory
|
Carya ovalis
|
Black Cohosh
|
Actaea racemosa
|
Bumblebee
|
Bombus sp.
|
Geometer Moth
Caterpillar
|
Family Geometridae
|
American Beautyberry
|
Callicarpa americana
|
Crossvine
|
Bignonia capreolata
|
Devil’s Walking Stick
|
Aralia spinosa
|
Sweet Pepperbush
|
Clethra alnifolia
|
Asian Multicolor Ladybug
|
Harmonia axyridis.
|
Purple Passionflower
|
Passiflora incarnata
|
Japanese Beetle
|
Popillia japonica.
|
White-Marked Tussock
Moth
(caterpillar) |
Orgyia leucostigma
|
Mountain Mint
|
Pycnanthemum sp.
|
Eastern Leaf-footed Bug
|
Leptoglossus
phyllopus
|
Scarlet Beebalm
|
Monarda didyma
|
Smooth Purple Coneflower
|
Echinacea laevigata
|
Fringed Bluestar
|
Amsonia ciliata
|
Mayberry/Juneberry
|
Vaccinium corymbosum
|
Carolina Grasshopper
|
Dissosteira carolina
|
Common Oblique Syrphid
Fly
|
Allograpta obliqua
|
Sleepy Orange Sulphur
Butterfly
|
Abaeis nicippe
|
Common Garden Snail
|
Cornu aspersum
|
Assassin Bug
|
Heteroptera: Reduviidae
|
Goldenrod
|
Solidago sp.
|
Water Hemlock
|
Cicuta maculata x
|
Maryland (Wild) Senna
|
Senna marilandica
|
Curly Dock
|
Rumex crispus
|
Deer-tongue Witch Grass
|
Dichanthelium clandestinum
|
Pearl Crescent
|
Phyciodes tharos
|
Flat-faced Longhorn Beetle
|
Astyleiopus variegatus??
|
Velvet Ant
|
Dasymutilla occidentalis
|
