Ramble Report October 25 2018

Today's Ramble was led by Dale Hoyt.

The photos in this post, except where noted, came from Don's Facebook album (here's the link).

Today's post was written by Dale Hoyt with assistance from Don Hunter.

Today's emphasis:  Tree refresher, Upper Parking Lot and Orange Trail

24 Ramblers met today.

Today's reading: Dale read the entry for October 26 from Donald Culross Peattie’s Almanac for Moderns:

It is nearly impossible to be sad, even listless, on a blue and gold October day, when the leaves rain down, rain down, not on a harsh wind, but quietly on the tingling air. They fall and fall, though not a breeze lifts the drooping battle flags of their foliage. You stand a moment before a late, last ash, watching. It seems as though the tree were actively engaged in shedding its attire, snipping it off, cutting it adrift. Pick up a leaf fallen at your feet, and examine the base of the leaf stalk. It feels hard to the touch; it is hollowed out. Had you a microscope, and a cut section of the leaf, you would see that indeed it had been cut off. The growth of a ring of callous cells, in a perfect ball and socket articulation, has predestined the fall. Wind need not tear the foliage down, nor decay set in. The tree itself passes invisible shears through its own auburn crown.

Today's route:

We headed up the steps to the upper parking lot and made our way down the island of trees separating the first and second section of the parking lot, checking out all of the trees and shrubs growing along the edge.  At the end of the island, we took the Orange Trail down to the bridge to the Flower Garden, which we crossed and returned to the Visitor Center, stopping only at the “warty” Beech to examine the Beech Drops. 

The dividing islands in the upper parking lot have a lot of different tree species, many of which are young, which means that their leaves are easily accessible. This makes it a good place to practice tree identification. In just that short strip of earth we found nine tree species.

Sourwood leaves are starting to turn color

The Sourwoods are beginning to turn color. Many of the leaves have a pinkish glow already. Sourwood is famous for the honey made from its nectar; some aficionados maintain it's the best honey in the US. Beeyards in the Appalachians were commonly surrounded with Sourwoods to capitalize on the higher price Sourwood honey commands.

Sourwood seed capsules, all that remains of the flower clusters of late spring

Sourwood flowers in the late spring and the white flowers are born in curving clusters that persist on the tree long after the petals have dropped. The remains of the flowers are a good identification aid for the tree. Other features are the long, narrow leaves that tend toward strap-shaped with pointed ends and,

Sourwood bark has deep furrows (or high ridges)

in mature trees, the deeply furrowed bark.

Sourwood midvein with reddish brown bristles

On the underside of the leaf the main vein has bristles that can be felt. The trees in the island are too young to have this bark, but we saw at least one example on the upper end of the Orange Trail. Another feature of the Sourwood is the twisted growth pattern of the trunk. You almost never see a straight sourwood trunk – it twists and turns as it grows upward. Some say that it is following the light, but other trees that also grow toward the light don't twist and turn as much as they grow toward the canopy.

Tuliptree leaves are also beginning to change color

Tuliptree leaves are unique with their four lobes that looks like the profile of a tulip. But that is not the origin of the common name. It comes from the greenish white flower that appears in early spring and resembles a tulip. This tree also has other common names, Yellow poplar and Tulip poplar, that are very misleading because the Tuliptree is not related to poplars. It's related to the Magnolias.

Red Maple leaves; note the red petioles and toothed edges.

As Linda tells us, there is something red in red maple throughout the year. In spring it is one of the first trees to flower and its flowers are red. The flowers are followed by leaves that have red petioles (the stalk that attaches the leaf to the tree). In the fall the leaves turn red.

The leaves typically have three lobes and each lobe has a toothed edge which distinguishes it from other maples in our area.

Corky wings on the branches of Winged Elm

Winged Elm leaves; note the almond shape large toothed edges. Some of the big teeth have smaller teeth on them.

There are several Winged Elms in the island. The name refers to a corky strip of tissue that is sometimes found running on either side along the length of small branches. But this is not always present and on larger trees it is difficult to see on higher branches, even if present. The shape of the leaf is pretty characteristic – it's like an almond, pointed at both ends and has a coarsely toothed margin. If you look closely at the marginal teeth you will find that each large tooth has 1 or 2 smaller teeth on it. Unusual for elms, the base of the leaf blade is symmetrical or only very slightly oblique.

Hophornbeam leaf (L) compared to Winged Elm leaf (R).

Hophornbeam is a tree that many Ramblers struggle to identify. The leaves superficially resemble those of Winged Elm, but are fatter, not almond shaped. They are also thinner and the marginal teeth are finer. Each large tooth has a smaller tooth on it, but the large teeth are much smaller than the large teeth of the Winged Elm.

Young Hophornbeams have smooth bark that resembles that of a young Black cherry tree. As the tree ages the bark changes in texture, becoming shredded, as if a cat scratched it to sharpen its claws.

The name has two parts: the “hop” refers to the similarity of its fruits to those of the Hop vine. The “hornbeam” may be a reference to a simple style of yoking a pair of oxen by tying a long stick to the base of their horns. The stick had to be durable and flexible to withstand the stresses put on it. In the Old World a strong, flexible wood from a tree called Hornbeam was used. Our Hophornbeam is related to its European cousin.

Wax Myrtle leaves

Wax Myrtle is a large shrub with leaves that are spatulate (wider toward the end), reminiscent of Water Oak leaves. But the leaves are clustered, not alternately arranged on the stem. The "wax" in the name refers to the thin layer of wax that covers the small fruits. In colonial times the wax was harvested by boiling the berries until the wax melted and floated to the top. It was then poured off and used to scent candles when mixed with bee's wax.

Wax Myrtle is evergreen and has separate sexes – it’s dioecious, meaning that different plants are either male or female. In order to get the wax berries you need a female plant and, of course, a nearby male plant.

The waxy berries are an important food for many birds, including warblers, cardinals, mockingbirds, catbirds, chickadees, vireos, flickers, robins and finches.

(I incorrectly stated that Wax Myrtle was in the plant family Myrtaceae, the eucalyptus family. It is not. It is in the family Myricaceae and only distantly related to the eucalyptus family.)

Sweet Gum leaves

Sweet Gum is easily recognized by the “gum balls” that it drops in the yard. Sometimes its leaves are confused with those of Maple trees. Here’s an easy way to tell them apart: Maples have opposite leaves – at the point on a twig or branch where you find a leaf you will also find a second leaf on the opposite side of the twig. Sweet Gum has alternate leaves – each leaf is attached singly to its twig.

Yaupon Holly leaves

A Yaupon Holly shrub with a few unripe (green) and ripe (red) berries started a discussion about caffeine.  Last week Ed told us that to make Yaupon tea all you needed to do was roast the leaves and steep them in hot water.

Ed also pointed out that Yaupon is the only North American species that contains caffeine. (A really good discussion of the scattered appearance of caffeine in flowering plants can be found here.)

Young Water Oak leaves; some unlobed, others with
a hint of a lobe

Young Water Oak leaves with pronounced lobes.
These lobes will be gone in the adult tree.

Water Oak. Young oak trees are often difficult to identify because their leaves often don't resemble the size and shape of leaves on older trees. Mature Water Oaks have leaves with expanded ends that slightly suggest two lateral lobes. The young sapling often has long, unexpanded leaves that resemble those of willow trees or Willow Oaks. Sometimes the leaves are divided into two or three thin lobes. So the small saplings we saw were probably Water Oak, especially since at the head of the island there is a larger Water Oak producing lots of small, spherical acorns. The year to year acorn production is less variable than in other oaks.

Small, spherical acorns of Water Oak. Also note the spatulate leave shape, wider at the tip.

Harvey wanted to know why this oak is called Water Oak. In nature it is most commonly found in moist, lowland situations like along streams. This is atypical for an oak, which are usually found growing in much dryer habitats. Water Oak is often used as a shade tree, so it can grow in other, dryer, situations. But it does not compete well with other trees outside its preferred habitat. Why is it planted in suburban lawns? It grows rapidly, for an oak, but is shorter lived than other oaks. It’s expected life span is 50-80 years.

Black Cherry is another tree that, like Hophornbeam, changes its bark as it ages. In its youth it has smooth bark with horizontal slits, called lenticels, scattered about the trunk. As it ages the bark darkens and takes on the appearance of, according to Emily, "crushed, burnt potato chips." You could see this change displayed by the younger branches in contract to the lower part of the trunk.

The upper part of the Orange Trail has a mixture of pines and hardwood species that is typical of the early stages in conversion of former agricultural land into a forest. Most of the pines here are Loblolly Pine. Their needles grow in bundles of 3 and are longer than three inches. The trunk of the mature tree is covered with large, reddish plates of bark and the cone scales carry sharp "prickles."

Shortleaf Pine

Scattered along the trail are a few Shortleaf pines with similar looking bark,

Shortleaf Pine bark with resin pits

but many of the bark plates bear “resin pits” or “pitch pockets,” small depressions about the diameter of a pencil lead.

Shortleaf Pine with resin pits exuding moisture

Some of these pits were surrounded by moisture but were not sticky, which they should be if they exuded pitch or resin. Shortleaf pine needles grow in groups of two and their length is less than 3 inches.

Shortleaf Pine cone

The cones are small, egg shaped, and are retained on the tree for many years after they have opened.

Southern Grape Fern

On our way down the Orange Trail we saw several Southern Grape Ferns, some with fertile fronds.

Beechdrops, the parasitic plant found attached to the roots of American Beech.

We saw two American Beech trees that were parasitized by a flowering plant called Beechdrops. The first was along a narrow section of the Orange Trail; the second, by the “warty” beech at the end of the trail to the Flower Garden. Beechdrops are flowering plants that are attached to the roots of the beech tree and get all their water and nutrients from that source. There is no need for them to make their own food and early in their evolutionary history they lost their chloroplasts and stopped making leaves. The result is the brown stems bearing flower buds or seed capsules that we saw today.

None of the Beechdrops we saw was flowering so, if you wonder what the flowers look like, this short video will give you a good look.

But wait, there's more! It turns out that Beechdrops have two types of flowers: those on the upper part of the stem that open and those on the lower part of the stem that never open. The lower flower buds self-fertilize and produce most of the seed. The uppermost flowers only rarely produce any seed. Even more unusual is their possible pollinator: ants. Very few plants are pollinated by ants (only three or four species are known, worldwide, to have ant pollinators). In one study researchers found Beechdrop pollen adhering to the bodies of ants that were climbing around the plant, so it seems a possiblity.

The dark encrustation on this twig is Black Sooty Mold

The dark material on the surface of the roots of this American Beech tree is the Black Sooty Mold growing on the honeydew produced by aphids on the branches above the roots.

If you looked carefully at the “warty” beech you would have noticed a black crust on the surface of its roots and on some branches. This is a Black Sooty Mold that grows on aphid poop, more politely called “honeydew.” Beech trees often harbor colonies of an aphid called the Beech Blight Aphid. Like all aphids they suck the sap of the tree which is a dilute sugar solution. The aphids absorb what they need and the rest, still sugary, is defecated. Since the colony stays in place the honeydew accumulates on any object below the colony, just like it does on your car when you park under a tree with aphids. Spores of the sooty mold are floating through the air and, landing on the sugar-enriched area, they begin to grow into the dark black crust we observed.

SUMMARY OF OBSERVED SPECIES:

Tuliptree	Liriodendron tulipifera
Sourwood	Oxydenron arboreum
Sweetgum	Liquidambar styraciflua
Winged Elm	Ulmus alata
Pipsissewa	Chimaphila umbellata
Red Maple	Acer rubrum
Wax Myrtle	Morella cerifera syn. Myrica cerifera
Shortleaf Pine	Pinus echinata
Water Oak	Quercus nigra
Southern Grape Fern	Botrychium biternatum
Yaupon Holly	Ilex vomitoria
Hophornbeam	Ostrya virginiana
Banded Tussock Moth caterpillar	Halysidota tessellaris
White Oak	Quercus alba
Crossvine	Bignonia capreolata
Poison Ivy	Toxicodendron radicans
Northern Red Oak	Quercus rubra
Oyster Mushroom	Pleurotus ostreatus
Beechdrops	Epifagus virginiana
Black Sooty Mold	Scorias spongiosa