I. Substrate-associated plants
1. Sourwood (Oxydendrum orboreum)
Sourwood gets its name from its acrid-tasting leaves. Sourwood is the sole species of sourwood and is found on ridges above the banks of streams in the midwest. The tree is short-lived, and rarely exceeds the age of 80 years. It is a deciduous tree with a rounded top and drooping branches, that develop into a broadly conical tree with branches that droop, giving it a unique appearance. Its leaves are alternate, simple, and oblong that taper to a point. Historically, these leaves were widely used to make tea to quench the thirst of mountain climbers. Its wood has also been used to make tool handles because it is hard and durable. Honeybees also produce rarely produced, delicious honey from their fragrant blossoms.
2. Eastern Hemlock (Tsuga canadensis)
Eastern hemlock is an acidophile whose bark was valued for its tannins by early Native Americans and settlers. The tannins found in the bark were also important for the tanning of leather. Medicinal teas were made from its bark and burn and sore ointments. Eastern hemlock populations in North America are threatened by the invasive Hemlock woolly adelgid, which infects and eventually kills the tree. The trees are historically long living, lasting up to 500 years. The trees are popular as ornamental trees due to their tolerance of a wide variety of environments, and their distinctive drooping branches.
3. Chesnut oak (Quercus montana)
Chestnut oak has historically been valued for its wood, which is commonly used as a domestic lumber species. Its dense, straight grains also made it an ideal option for long-lasting firewood. Livestock and humans have also valued the chestnut oak for its edible acorns, which are large and have good flavor. Also known as the rock oak due it its presence in rocky habitats, this tree is an important specimen that is identified through its heavily ridged dark bark–the thickest bark of any eastern North American oak. Many of the chestnut oaks in the Appalachians are trees that regrew from stump sprouts after being logged.
4. Huckleberry-blueberry (Vaccinium ssp.)
The blueberry shrub is a common and widespread genus of shrubs in the heath family, whose well-known edible fruits are used in a variety of ways. Every berry in the Vaccinium group is edible, great tasting, and healthy for humans. Historically, they have been used as a traditional medicine in different cultures, and their berries have been widely consumed as food. Their berries have a significant economic impact as one of the best, most easily accessible sources of antioxidants. Their fruits have been widely recognized as moderators of cellular pathways involved in pathological conditions.
II. Biotic Threats to Forest Health
1. Butternut (Juglans cinerea L.) – The health of the butternut has severely deteriorated over the past half century due to a disease caused by the fungus, Ophiognomonia clavigigentijuglandacearum, which has caused the remaining population of the butternut to decline. This disease known as the “butternut canker” has caused widespread mortality of the butternut throughout North America. Studies evaluating the genetic structure and diversity of the butternut have been conducted to better manage the declining species. Hybridization of the butternut with Japanese walnut has been important in identifying and reproducing resistant butternut. Restoration efforts have been focused in parks where the soil is well-drained and moist–often near streambanks. Due to its shade intolerance, it must be planted in areas without competition from above. Butternut restoration is underway and offers the opportunity to reduce the effects of the butternut canker pathogen, specifically when efforts are focused on forest stands optimal for tree growth and recruitment. Local breeding of resistant hybrids has been essential in restoring the health of the butternut.
2. American chestnut (Castanea dentata) – The health of the American chestnut has been compromised by several biotic and abiotic stressors–specifically chestnut blight or chestnut bark disease, which is caused by the fungus Cryphonectria parasitica. This fungus enters wounds on the tree and grows in and under the bark–eventually causing the mortality of the tree. Sprouts are formed at the root collar, which contains dormant embryos. These sprouts grow and are wounded, infected, and killed–which causes a never-ending cycle of mortality in the trees. These cankers have caused major damage to the health of the American chestnut, whose chances of evolving resistance are slim to none due to the ability of the chestnut blight disease to infect the sprouts before they become sexually mature. Restoration efforts have been made through the use of hypovirulent strains, which have been used to treat cankers on the trees found in orchards and forests. The strains were grown on agar mediums and put into holes in the bark–killing the cankers. The treatment of every canker within reach for a period of 4 years prevented the expansion of the cankers–establishing biological control of the chestnut blight disease in American chestnuts in Connecticut. These efforts have been most successful in orchards, where trees are closely spaced and the shade and competition for nutrients suppress sprout growth. Breeding programs have also been put in place to maintain the American chestnut populations by creating resistant hybrids to the cankers.
III. Appalachian Gametophyte
1. The common name of Vittaria appalachiana is the Appalachian gametophyte. It is a temperate member of the exclusively tropical lineage that inhabits the Appalachian Mountains and Plateau of the eastern United States. It grows atop porous rock outcrops that are typically adjacent to water. Its distinctive feature is that it exists exclusively as a vegetatively reproducing gametophyte. It is one of only three ferns in which mature sporophytes have never been observed because it reproduces asexually via gemmae, which when mature can separate from the gametophytes, disperse short distances, and grow into new independent, but genetically identical individuals.
2. Fern gemmae are large in comparison to spores (0.2-1.9 mm in length), and generally considered too large for wind dispersal over long distances. Gemmae are consequently dispersed by short distances through 1) wind, 2) water, or 3) animals (short distances via slugs and ants). A 1995 publication by Kimmerer and Young indicated animal-based dispersal via slugs. The notion of limited dispersal capability is supported by the absence of this species north of the last glacial maximum beyond which a transplant study has shown they are able to survive.
3. Recently disturbed areas or other substrates that appear suitable for the species remain frequently uncolonized, while the species thrives on seemingly similar nearby substrates. With the evidence of limited dispersal capability in the absence of the species north of the last glacial maximum, this combined data suggest that spore dispersal from a fully functioning sporophyte must have been responsible for the current distribution of the Appalachian gametophyte. The truncated range of the species in southern New York also indicates that the gametophytes have lost the ability to produce mature, functioning sporophytes sometime before or during the last ice age.
4. The possibility that the current populations of the Appalachian gametophyte could be sustained via long-distance dispersal from a tropical sporophyte source can be rejected based on past allozyme studies combined with the truncated range of the species in the southern portion of New York. The monophyly of the species in plastid analysis indicates that dispersal from the tropics occurred in a singular occurrence, although the situation is more nuanced in the nuclear tree, where the Appalachian gametophyte allele is resolved outside of the larger clade. Because the dispersal of gemmae does not account for the wide range of the species, it is likely that a fully functioning sporophyte of the species existed and thrived in North America in which temperatures were more favorable for tropical growth in the Appalachians. In this scenario, the current distribution of the Appalachian gametophyte would be solely due to spore dispersal, with the sporophyte becoming extinct before or during the Pleistocene glaciations, which is supported by its apparent inability to extend northward beyond the limit of the last glacial maximum. If it produced sporophytes after the glaciers had receded, spore dispersal could’ve been widened further north to mirror the distribution of other eastern North American fern species.
IV. Specific assignment – two plants with bilateral symmetry
1. Common jewelweed (Impatiens capensis)
The common jewelweed, also known as the spotted touch-me-not plant, is an annual plant native to North America, which is known for its ballistic projectile seeds, which burst when touched. It has a bilaterally symmetric orange flower that is funnel-shaped with a long narrow spur.
2. Great Blue Lobelia (Lobelia siphilitica)
The great blue lobelia is a bilaterally symmetric flower whose petals are a vibrant blue-purple color. Its petals and sepals are fused into a cup shape. It is an herbaceous perennial plant, that is not a true perennial because its shoots and roots die after the plant sets seed. The new shoots grow quickly from the lower leaf axils and put down new roots, producing a new plant the following year.
V. Miscellaneous Other Observations
1. Japanese stiltgrass (Microstegium vimineum)
Japanese stiltgrass is a “grr-argh” plant, as Dr. Klips would describe. It is an annual grass that is adapted to a variety of habitats and is well-tolerant to low light levels. This grass is invasive and produces dense grass that reaps the nutrients from neighboring plants. It threatens native vegetation in floodplains and areas prone to natural scouring. It became a problem after it was used historically as packing material for transporting porcelain from Asia to North America in the early 1900s. Unfortunately, after this introduction, Japanese stiltgrass has been a prevalent problem in many areas–invading and competing for nutrients in moist, well-drained areas.
2. Beechdrops (Epifagus virginiana)
Beechdrops are an obligate parasitic plant that grows on the roots of the American beech. Its appearance presents itself as an inconspicuous brown stem that produces two types of flowers: 1) cleistogamous flowers that self-pollinate without opening, and 2) chasmogamous flowers that are sterile, but open. The roots of the beech tree release a chemical that triggers the germination of the beechdrop, with older beech trees releasing more chemicals that trigger it. The parasite produces a haustorium that grows on beech tree roots, which sap nutrients from the host because beechdrops are not photosynthetic plants.
3. Spicebush (Lindera benzoin)
Spicebush is a “scratch-and-sniff” plant whose vibrantly red-colored fruits and bark have a distinctive peppery-citrusy aroma. During the American Revolution, the berries from the spicebush were dried and powdered and used as a substitute for allspice. The bark of the spicebush was used as a cinnamon substitution. The North American Iroquois and Ojibwa tribes often used spicebush as a medicinal tea to treat fevers, colds, and inflammatory issues. It was also used as a way to relieve stagnant gas in the stomach. The spicebush is also home to the Spicebush Swallowtail Butterfly and larvae. Its fragrant taste makes it a repellant for deer and other grazing wildlife.
4. Snakeskin liverwort (Conocephalum salebrosum)
Snakeskin liverwort gets its name from its uniquely-textured shiny leaves, which, true to its name, resemble snakeskin. It is a nonvascular plant with an affinity for wet environments, most often being found on rock surfaces or thin soil. It grows frequently along streams and moist cliffs and rocks, and has clear diagnostic features. The structure of its pores of the archegoniophore and dorsal thallus surface make it easily identifiable to most botanists.