Autumn in the Hudson Valley: Part 2 (Foliage)

The first tree species to begin the color change is the red maple (Acer rubrum).  It progresses from a glaucous green to a deep and vivacious scarlet. Often in mid-August in watery or swampy environs the transformation has already begun. Water is key to the premature reddening, without which, trees may not be imbibed with their autumnal hues for another month or more. It is not entirely understood why this occurs.

The red maple is a highly adaptable species, and is one of only a very select few that can successfully colonize the three main environmental realms: hydric (swamps, river or stream edges, and other water-laden locales), mesic (upland locations with rich, thick, and well drained soil), and xeric (dry, hot, and rocky with a thin and/or poor soil base, often found on high hills or mountains, especially on southern facing slopes).

Usually the next tree to change is the sugar maple, which garners a vibrant, highlighter-like orange. This upland species is often found mixed in a typical forest environment, and is often located in residential areas where it is commonly planted as an ornamental or for the sweet sap that can be collected in the spring. Before other trees of the neighborhood have even a hint other than a summer green, the sugar maples develop orange patches. It is usual to see one side of a tree completely morph before the other begins, and it can be several weeks before the entire tree is a solid shade of pumpkin.

After the sugar maple, many other species gain the colors of autumn simultaneously and it is difficult to predict which order they will follow. For this reason, I will describe the various tree/shrub species that inhabit our area from red to violet, or in the order of the color spectrum. To my knowledge, no tree or shrub species has a blue or indigo related tint, and as such, these shall be omitted from the list.

Apart from the red maple, tupelo, or the black gum tree, possesses the most stunning dark red, or crimson foliage of the forest. Each falling leaf is a drop of blood. When the limbs are bare, the ground beneath looks as if some terrible massacre has unfolded there, leaving no survivors of either party. Even when dried, and other species would have lost most of their coloration, it is remarkably well preserved in those of the tupelo.

 

While blueberry bushes have the distinction of producing the only edible fruit in the country that has a true blue coloration, in the fall its leaves also turn blood red, giving the impression of a burning bush. The Shawangunk Ridge, being the extreme western border of the Hudson Valley, is legendary for producing vast scarlet fields in mid-October. Sam’s Point Preserve, along with Minnewaska State Park, are two prime locales to view this undulating sea of red. There are probably no better spots in the state to witness this epic transformation.

The brightest and most well known color of the fall belongs to the orange sugar maple. It has become a widespread staple of the season, better than probably any other species.

A smaller, thinner tree in the orange spectrum that usually receives less attention than its proliferic maple cousin, yet has hues just as dazzling is that of sassafras. This species primarily resides within the mid to upper levels of the understory and has leaves which quite distinctly resemble dinosaur footprints. Each leaf usually has 3 deeply curved lobes that make it look as if it’s trifoliate, similarly to a clover; although sometimes they are of a slightly different morph and more closely resemble mittens, having one large lobe attached to a smaller one that is both sharper and pointier at the tip, the thumb of the leaf as it were.

While frequently exhibiting an orange coloration, slightly darker than sugar maples, sassafras also shows significant variability in its color display. At times, every leaf on the tree can be a dandelion yellow or perhaps scarlet, with red-orange undertones intermixed.  It’s important to note that every tree, like that of a person, has a different “personality” and like a mood ring, displays each of its emotions in a separate color, based on the level of its stress and rapidity of biochemical degradation within the leaves that ultimately determines color.

Sassafras roots were once used as a main ingredient of root beer and sassafras tea until being phased out by the FDA in 1960 once safrole, an oil produced by the tree, was found to be mildly carcinogenic and damaging to the liver. The ban on sassafras tea expired in 1994. It is now believed that a can of alcoholic beer poses a greater carcinogenic risk than that of a cup of tea.

Early on in the 17^th century, sassafras was the nation’s second largest export, falling just behind tobacco. In Europe it was utilized to treat a variety of health disorders.

Moving into the area of varying degrees of yellow, witch-hazel has the brightest leaves, with each exhibiting a warm, sunny yellow. Witch-hazel is an understory species, rarely rising above a dozen feet. Its undersized stature ensures that an individual passing through the woods will get a close observation, especially of its petite flowers.

This shrubby tree begins to bloom in mid-October and may persist until the closing of November, a rare bloom date for trees. Its flowers are generally unseen though, despite being one of the most common trees in the Hudson Valley. This is due in part to their small, yellow flower clusters that blend into the fall foliage making them nearly perfectly inconspicuous.

The leaves and bark of witch-hazel are potent astringents and have been harvested for centuries for use. Products containing it can still be found in the pharmacy.

The tulip tree or yellow poplar is the tallest tree to be found in eastern forests, rising in height up to 150 feet. It receives its name from the large yellow and orange blossoms that appear on the uppermost branches in the spring that superficially resemble tulips. Native Americans utilized these trees to make their dugout canoes. The soft wood and perfectly straight trunks made this species ideal for such use.

Tulip trees have a slow transition compared to other species. Frequently the upper, leafy portion of the tree is a mosaic or checkerboard of yellow and green, with each individual leaf changing at its own pace. Due to their immense height, most of the in-depth leaf peeping will have to be done on the ground when the leaves have finally become detached. If you look up into its canopy all that will be glimpsed is a nebulous mass of yellow, despite the size of the leaves. Each leaf of older trees is rather substantial, often being nearly as wide as two hands placed side by side.

Black walnut also has a coloration similar to the tulip tree. Aside from its tasty nuts which are readily consumed by animals and man alike, its dark hued wood is highly prized and quite valuable. It’s different from the trees already discussed in that its leaves are pinnately compound, meaning each leaf stalk contains multiple lanceolate shaped leaves that are arranged in an alternating pattern on each side. The stalks very superficially resemble a fern frond.

Anyone who has ever looked beneath a black walnut tree has probably noticed that very few plants can be found growing there. This is not due to a lack of sunlight.

Black walnut is an “allelopathic” species, meaning it produces a substance which alters the growth of other plants. All parts of the tree contain a growth inhibiting substance known as juglone. This natural herbicide is released via decomposing leaves and nut husks, but live roots will also discharge small quantities as well. Juglone is very weakly water soluble, and as a result, this chemical remains sequestered in the soil surrounding the tree and builds up to levels where it prevents other plants from competing with it.

The American chestnut, once one of the most common trees in the eastern U.S. it is now quite rare in our forests. In the early part of the last century Cryphonectria parasitica, a fungus accidentally introduced from Asia, quickly killed off 99% of the trees within a couple decades. Trees are still occasionally found in northeastern forests, but by the time the tree reaches approximately 30 feet in height the fungus will have killed it. The roots can survive the fungus, though, and will regenerate the tree until once again it succumbs to the blight. The historic Bear Mountain Inn was constructed from chestnut lumber taken from dying trees in Rockland County that were part of Bear Mountain and Harriman State Parks.

While it’s usual to see the occasional tree here and there in the woods, small remnant groves are still extant in a few areas. I’ve even seen trees flower in the spring and produce nuts, an extremely rare occurrence east of the Appalachians. These nuts, however, not being fertilized, were half their normal size and abortive. The trees that produced the seeds were discovered studded on the slopes of Schaghticoke Mountain, just over the NY border along the Appalachian Trail in Connecticut. This wild peak with massive boulders, often larger than pick-up trucks, jumbled every which way on the mountain from the base to the 1,330 foot summit, contains an ecosystem very similar to the one that existed across the entire eastern U.S. prior to the spread of the blight. While trees do not attain the height they once did, their numbers are still significant, although still well below the pre-blight range, where every 1 in 4 trees in Appalachian forests was an American chestnut.

The mountain laurel, being an evergreen species like the pines, does not lose its foliage in the fall, but rather retains the verdant luster of the summer. It stands out the most at the conclusion of the season, when most other plants have lost their leaves.  These shrubs look out of place among the russet detritus and scrawny limbs of the forest, but enhance the landscape so much more with their differing ideology. Has spring arrived early or has summer lingered? It’s hard not admire their fortitude and resolve to hold onto what they have earned. This comparatively small shrub stands beneath its lofty kin, ignoring their communal gestures and patterns and follows its own bend. We can learn a great deal from Nature.

In the spring the mountain laurel produces the most exquisite white to dark pink flowers. The whole plant ignites in blossoms.  An entire mountain top may be cloaked in the cologne-like aroma emanating from them. While briefly intoxicating, breathing in too much of this pungent scent may produce a migrane. Despite being nibbled by deer, all parts of this plant are poisonous to humans. And the honey produced by bees primarily visiting them may be toxic to consume.

Very few woody species have violet colored leaves in the fall. It’s the rarest of colors. Yet, maple-leaf viburnum dishes it out extraordinarily well, a full-bodied violet as strong and deep as those “purple mountain majesties” we reminisce about. This plant also fruits around the same time of the color transition. A cluster of berries can be found on most of the taller stalks that comprise the plant. Each grouping contains upwards of perhaps 20 berries that are situated above the brilliant leaves. Berries are similar in appearance to black currants, with a tinge of blueberry.

Ash trees may also produce leaves with a bit of violet to them, but this is the least common color these trees present. Like sassafras, the color variability is high and may be either yellow, orange, red, or violet, with varying degrees of colors intermixed within each individual leaf. Ashes produce a pleasing purplish tint, but rarely does a tree come solely in this hue.

There are several species of ash present in our area and each is being threatened by the emerald ash borer, an invasive species which is responsible for killing millions of trees in upstate New York. They are quickly descending downstate and within a decade most of our ash trees might go the way of the chestnut, leaving us with only memories of what once was. They have already been confirmed present at West Point.

The American beech is one tree worth noting that doesn’t fit into our neatly organized list. Instead of developing a vibrant or intense autumnal color, its leaves very slowly acquire a sober light brown. It’s one of the last species to change, holding onto summer as long as possible. Its stiff and papery leaves are like those within a newly bound book.  Despite them not displaying some grand and lively color these pages are definitely worth reading.

As Americans it should be our passion to immerse ourselves in the scenery and remarkable beauty of our native land, seeking to preserve its continuity whenever possible in an already too fragmented landscape. Our forests and the diversity it contains has no peer elsewhere on this globe. In other areas of the world where deciduous forests exist, few exhibit the color scheme that presents itself here, draping themselves mostly with unspirited yellows and browns that lack both liveliness and intensity. Furthermore, all of continental Europe has only 85 tree species, while the eastern half of the U.S. contains over 110 different varieties.

Adrien van der Donck, an early settler of the Hudson Valley when the region was still under Dutch rule, succintly sums it up: "I admit, that I am incompetent to describe the beauties, the grand and sublime works wherewith providence has diversified this land."