Ramble Report April 25 2019

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.

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, nor mail 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.

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:

Pale Yellow Trillium with white petals

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.

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.

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.

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.

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.

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.

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.

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. 

Celandine Wood Poppy with fuzzy fruits.

Leatherwood, that bloomed in early March, has set fruit.

Mayapple fruit.

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.
 

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:

Dove’s-foot Crane's-bill visited by syrphid fly

Corn Salad

Lyreleaf Sage

Butterweed

Butterweed, an annual ragwort in the same genus as the Golden Ragwort is found principally in moist areas like flood plains.

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.) 

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.

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.

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:

American Wisteria	Wisteria frutescens
American Hophornbeam	Ostrya virginiana
Pale Yellow Trillium	Trillium discolor
Painted Buckeye	Aesculus sylvatica
Golden Ragwort	Packera aurea
Black Cohosh	Actea racemosa syn. Cimicifuga racemosa
Rattlesnake Fern	Botrychium virginianum
Christmas Fern	Polystichum acrostichoides
Cinnamon Fern	Osmunda cinnamomea
Celandine Wood Poppy	Stylophorum diphyllum
Leatherwood	Dirca palustris
Foam Flower	Tiarella cordifolia
Atamasco Liliy	Zephyranthes atamasca
Mayapple	Podophyllum peltatum
Yucca	Yucca filamentosa
Yucca Plant Bug	Halticotoma valida
Longleaf Pine	Pinus palustris
Pine Needle Rust	Coleosprium sp.
Fringed Bluestar	Amsonia ciliata
Corn Salad	Valerianella radiata
Low Hop Clover/Hop Trefoil	Trifolium campestre
Blue Toadflax	Nuttallanthus canadensis
Lyreleaf Sage	Salvia lyrata
Field Madder	Sherardia arvensis
Dove’s-foot Crane's-bill	Geranium molle
Eastern Calligrapher	Toxomerus germinatus
Butterweed	Packera glabella
Rivercane	Arundinaria gigantea
Indigo Bunting	Passerina cyanea
Brown-headed Cowbird	Molothrus ater
Kentucky Warbler	Geothlypis formosa
Carolina Wren	Thryothorus ludovicianus
White-Marked Tussock Moth	Orgyia leucostigma