Ramble Report April 25 2019
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:
Seeking what we find in the Dunson Garden down to the River Cane.
26 Ramblers met today.
Announcements:
Next Weds., May 1, Emily will lead the monthly guided walk at Sandy Creek
Nature Center. Walk starts at 9 a.m.; coffee and snacks afterwards.
Show and Tell:
Robert was walking into the Conservatory building this morning when he heard a
“thwack.” A bird had flown into the glass and died.
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| Rose=breasted Grosbeak,killed by flying into a glass window. |
It was a lovely
Rose-breasted Grosbeak, on its way north. These are usually only seen at our
feeders for a week or two during spring migration.
Today’s reading:
Dale read the entry for April 26 from Donald Culross Peattie’s Almanac for Moderns.
ON this day in 1785 was born Jean Jacques Audubon, in Santo
Domingo, natural son of a French captain of Nantes, who was brought up in
France by the captain’s forgiving wife, spoiled, petted, raised as a little fop
– this man who was to give himself to the American wilderness. When first he
came to Philadelphia, a young foreigner, a dilettante, a country gentleman, we
see him out shooting in the woods in satin breeches,
wig and pumps. We see him encounter
there his English neighbor, Bakewell, who takes him home to meet a blue-eyed
daughter, rising tall among the dogs by the fire-Lucy Bakewell, his wife to be.
But Nature has her eye upon the man in the elegant
clothes. First, she must teach him that you cannot well dream out of a window
in a counting house, you cannot play the indigo market without knowledge, normail a thousand dollars in an open envelope, nor
manage a mill while you are out hunting vireos and wrens, painting warblers and
cardinals. Then, when she had broken him with misfortunes, she sent him out
into the Kentucky wilderness, singing to it with his Cremona violin at his
shoulder, and to his young bride.
There amidst the beeches, the passenger pigeons and the
wild deer, John James Audubon let his gold hair grow long to his shoulders,
learned to handle a fire . . . and a gun. There, unknown to
all the world, he painted birds, watched
them, lived with them, knew them as he knew his children or his Lucy. In the
cane brakes, on the Mississippi, in the Texas bayous, the palmetto islands of
Florida, the sea-girt bird rocks of the Gaspe, this child of Nature, untaught
in science, saw what he saw and knew what he knew.
Today’s route:
Through the Children’s Garden and down the Shade Garden walkway to the first
mulched path at the second switchback. Then downhill on the mulched path to the
Dunson garden. Through the garden to the power line and down to the river. Then
return to the Visitor’s center for refreshments (a cake to celebrate Halley’s
birthday).
LIST OF
OBSERVATIONS:
Children’s Garden Arbor:
The Yellow Jessamine vines we’ve seen on previous rambles
have been removed.
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| American Wisteria (double click to enlarge) |
In their place are American Wisteria vines with young inflorescences.
We look forward to seeing how soon these vines will be clambering across the
arbor.
Dunson Native
Flora Garden:
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|
| Pale Yellow Trillium with white petals |
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| Pale Yellow Trillium with light yellow petals. |
We found Pale Yellow Trillium throughout the Dunson Garden. There was a lot of discussion as to whether these plants were Yellow Trillium or Pale Yellow Trillium. A diagnostic character is the presence of a point at the tip of the petal in Pale Yellow Trillium.
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| Palmately compound leaf of Painted Buckeye; five leaflets arise from a single point on the leaf stem (petiole). |
Buckeyes are
easily identified by their palmately compound leaves. (Palmate means that the
leaflets are all attached to the leaf stem (the petiole) at the same place. In
contrast, pinnately compound leaves have the leaflets attached to the leaf stem
at many different points. Examples of trees with pinnate leaves are: hickory,
ash, walnut and pecan.)
Several of the
leaves on a few of the Painted Buckeyes had wilted, possibly caused by the
caterpillar of a moth, the Buckeye Petiole Borer. The caterpillar feeds internally
in the leaf stem, eventually destroying the vascular system in the stem. This
prevents water from getting to the leaf blades and they wilt. We have no direct
evidence that this moth is the responsible agent. Bugguide.net has a photograph
of the caterpillar feeding on the leaf of a different species of
Buckeye.
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| Golden Ragwort is setting seed. |
Golden Ragwort is
going to seed all over the garden. A few plants are still flowering but most
are producing seeds attached to fuzzy white parachutes, similar to those seen
on dandelions. On windy, dry days these will be carried away in the breezes,
resulting in the rapid spread of the ragwort over the garden. This ability to widely
disperse their seed often makes ragworts problem plants in the garden. But it
makes the ragworts happy.
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| Black Cohosh developing nflorscence. |
Black Cohosh inflorescences
are just now beginning the develop. Soon they will bolt to heights of five or
six feet and be covered with small, white flowers.
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| Rattlesnake Fern Notice that the fertile frond arises from the stem near the leaves. This distinguishes it from the Grape Fern which has a fertile frond arising from the soil near the plant. |
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| Closeup of the fertile frond to show the spore producing structures. |
Spring is the time
for Rattlesnake ferns to pop out of the ground. They produce two types of fronds:
sterile and fertile. The sterile fronds are leafy and delicately dissected.
They are called sterile because they do not produce spores. Each plant produces
a single, fertile frond. The green portion of the frond develops tiny spherical
structures that produce the spores.
Christmas ferns
are also beginning to prepare for spore production, but these plants divide the
responsibility for reproduction differently from Rattlesnake Fern. Many, but
not all, of the fronds develop spore producing structures on the underside of
the outer third of the frond.
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| Spore producing structures on the underside of the pinules of a fertile frond. |
The pinnules of this portion of the frond are
distinctly smaller and the sori (the spore producing structures) will be a
rusty brown when mature.
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|
| Cinnamon ferns with fertile fronds |
Cinnamon fern is
another fern with distinct fertile and sterile fronds. The fertile fronds grow
from the center of the cluster of sterile fronds and are wholly devoted to
spore production. The fertile fronds are about two to three feet in height and
cinnamon-colored.
Spores vs. Seeds
Although spores
and seeds perform the functions of dispersal and reproduction, they are very
different. A spore is a single cell and carries no nutrients. It has a resistant
shell that enables it to survive for a period of time if it lands in an unfavorable
environment. When it does germinate it develops as a green, photosynthetic
organism that initially looks like a algal filament, a green thread capable of photosynthesis. That ability to
photosynthesize is crucial, because the spore has no stored food. After germinating it can only survive if it can make enough food to support its own growth.
On the
other hand, seeds contain an embryonic plant plus a source of food provided by
their parent. They too have a protective coat and often can survive in the
place where they land until conditions become more favorable. Then they can
germinate, but they don’t have to worry about making enough food to support
their growth – they have that resource provided by their parent and it is
usually enough to support them while they get established.
Fern reproduction
Plants (and some
animals) can reproduce vegetatively – the offspring are clones — identical copies of the
parents. Examples are taking cuttings of plants, or, in primitive
animals, cutting the animal into pieces, each of which can regenerate the whole
animal.
In animals sexual
reproduction involves the formation of gametes (egg cells or sperm cells). The gametes then join together (fertilization) and
the fertilised egg (called the zygote) multiplies and differentiates into a multicellular organism. The
resulting organism resembles, but is different from its parents as well as
different from any of its siblings produced by the same parents.
Plants add a new wrinkle to the sexual reproduction process, illustrated by the life cycle of a fern.
Start with the green, leafy plant, like a Christmas Fern. It produces spores. Each spore is a single cell, but that cell contains only half the number of chromosomes that are found in the cells of its parent plant. This makes the spore equivalent, genetically, to an animal gamete (egg or sperm cell), that also has only half the genetic material found in animal cells. In animals the egg and sperm don’t live very long if they don’t meet up with one another. Unfertilized eggs die after a short period of time, as do sperm cells that don’t manage to fertilize an egg.
The fern spore does not seek out an egg. Instead it grows into a green plant, albeit one much smaller than the familiar Christmas fern. It is that tiny plant that produces eggs and sperms. In the presence of water (think heavy dew) the sperm cells swim to nearby plants and fertilize the egg cells that they find there. The fertilized eggs now divide and grow into the plant we recognize as the Christmas Fern.
We recognize the different kinds of plants in this life cycle by the kind of reproductive cells they produce. The plant that produces spores is called the sporophyte (literally, spore-plant). The plant that produces gametes is called the gametophyte (literally, gamete-plant). The life cycle of the fern consists alternating sporophyte and gametophyte generations.
In genetic terms the sporophyte generation has two sets of chromosomes in each cell. Each spore has only one set of chromosomes so the gametophyte has only one set, as well. The fusion of egg and sperm to produce the sporophyte restores the number of chromosomes in each cell to two sets. If ferns were people the sporophyte would have 46 chromosomes in every cell and the gametophyte would have 23 chromosomes in each cell.
This life history pattern is like something out of a science fiction novel. Imagine if we all had the same, undifferentiated sex. We wouldn’t even have a concept of sex. Everyone could produce children. But those children that would become sexually mature hermaphrodites that would then mate and produce another generation of sexless individuals.
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| Celandine Wood Poppy with fuzzy fruits. |
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| Leatherwood, that bloomed in early March, has set fruit. |
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| Mayapple fruit. |
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| Yucca Plant Bugs |
The Yucca at the bottom of the Dunson garden are covered with Yucca Plant Bugs. The large inflorescences are still nestled in the center of each plant, but will shoot up to a height of four or more feet in the next few weeks.
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| Longleaf Pine with Pine Needle Rust |
The solitary Longleaf Pine near the Yucca has been invaded by Pine Needle Rust, caused by a rust fungus, Coleosporium sp. It does little harm to the tree. The orange patches are the spore producing surfaces of the fungus.
Powerline Right of Way:
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| Dove’s-foot Crane’s-bill visited by syrphid fly |
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| Corn Salad |
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| Lyreleaf Sage |
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| Butterweed |
Butterweed, an annual ragwort in the same genus as the Golden Ragwort is found principally in moist areas like flood plains.
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| Ramblers examine the Rivercane. Depth of flood water at this point was over our heads. |
Two years ago Rivercane was planted in the bottom of the floodplain in an effort to restore a unique southern habitat, the canbrake. Our recent rains brought the river over the banks and up the flood plain, completely immersing the Rivercane. It survived the inundation with no sign of damage. (It really is adapted to the riverside environment.)
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| White-marked Tussock Moth caterpillar on American Wisteria |
The caterpillar of the White-marked Tussock Moth feeding on the American Wisteria emphasizes Doug Tallamy’s message in Bringing Nature Home: Chinese wisteria isn’t recognized as food by our native moths and so it does not provide any food to birds and other animals that could eat herbivorous insects feeding on the plant.
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| Looking up the flood plain from the river. The area covered by the flood is marked by the brown silt marked vegetation well beyond the fence line. |
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| Slumping of the river bank caused by recent floods. A few more floods like this will remove the Orange Trail in this area. |
SUMMARY OF OBSERVED SPECIES:
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American Wisteria |
Wisteria |
|
American Hophornbeam |
Ostrya |
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Pale Yellow Trillium |
Trillium discolor |
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Painted Buckeye |
Aesculus |
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Golden Ragwort |
Packera |
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Black Cohosh |
Actea |
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Rattlesnake Fern |
Botrychium |
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Christmas Fern |
Polystichum |
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Cinnamon Fern |
Osmunda |
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Celandine Wood Poppy |
Stylophorum |
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Leatherwood |
Dirca |
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Foam Flower |
Tiarella |
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Atamasco Liliy |
Zephyranthes |
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Mayapple |
Podophyllum |
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Yucca |
Yucca |
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Yucca Plant Bug |
Halticotoma |
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Longleaf Pine |
Pinus |
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Pine Needle Rust |
Coleosprium |
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Fringed Bluestar |
Amsonia ciliata |
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Corn Salad |
Valerianella |
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Low Hop Clover/Hop Trefoil |
Trifolium |
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Blue Toadflax |
Nuttallanthus |
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Lyreleaf Sage |
Salvia |
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Field Madder |
Sherardia |
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Dove’s-foot Crane’s-bill |
Geranium |
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Eastern Calligrapher |
Toxomerus |
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Butterweed |
Packera |
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Rivercane |
Arundinaria |
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Indigo Bunting |
Passerina |
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Brown-headed Cowbird |
Molothrus |
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Kentucky Warbler |
Geothlypis |
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Carolina Wren |
Thryothorus |
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White-Marked Tussock Moth |
Orgyia |