We have a new contributor but also a longtime reader and a planet ecophysiologist, Howie Neufeld of Appalachian State University. I met him when I gave a seminar at that beautiful school high in the mountains. Howie’s captions and IDs are indented, and you can enlarge his photos by clicking on them.
Fall is the busiest tourism season in the Southern Appalachians. While most people come to see the fall color display by the trees, there are also numerous wildflowers that present at the same time. Here is a sampling of those flowers and trees for your enjoyment. All photos taken with a Google Pixel 7 phone.
Numerous goldenrod species bloom late summer into the fall. The species shown here is either Solidago canadensis or S. altissima. If altissima, then all are hexaploids. In the Midwest, you can find diploids, tetraploids and hexaploids. My student Katie Krogmeier showed that Midwest and eastern hexaploids differ in morphology and physiology, perhaps because they are neopolyploids (recently evolved after the polyploidy event). Why there are no diploids or tetraploids in the East is a mystery:
Closed Gentian (Gentian clausa), a species that flowers in the fall. Only insects strong enough to force petals open can pollinate these plants (usually bumblebees in the genus Bombus):
Blue Wood Aster (Symphyotrichum cordifolium) is common along trails. Younger disc flowers are yellow and attract more pollinators than the older red ones. The same phenomenon is found in White Wood Aster (Eurybia divaricata), which also flowers late in the year. Coevolution at its best:
Galax urceolata, also known as beetleweed, is a native evergreen understory herb. Leaves exposed to bright light when it is cold turn red by synthesizing anthocyanins and will green back up when it warms in the spring. The leaf in the foreground had another leaf shading one side, which is why that portion is still green. The tough leaves are often used for table decorations in restaurants and the species is subject to poaching. Our research on Galax can be found in this paper (click here).
Witch Hobble (Viburnum lantanoides) is common at moderately high elevations in the mountains of NC – this one from Elk Knob State Park. Branches that touch the ground can root, creating a tripping hazard, hence, its other name, Hobblebush. Its leaves have this splotchy pattern of anthocyanin accumulation, but eventually the entire leaf turns a deep reddish purple:
Witch hazel (Hamamelis virginiana) flowers in October when it can be cold. Flowers may be pollinated by a wide variety of flies and and small bees , while at night it may be the Winter Owlet Moth (Actronicta hamamelis), which can raise its body temperature on cold days by shivering, enabling it to seek out flowers. It detects them by volatiles released from the flowers.
American Beautyberry (Callicarpa americana) has unusual, purple-colored fruits in the fall. A recent study (click here) showed that species with purple fruits are the best at attracting seed dispersers:
American Mountain Ash (Sorbus americana) grows above 4,500’ elevation in NC, like this one on the Rough Ridge Trail on the Blue Ridge Parkway. Numerous bird species and mammals such as deer, bears and squirrels feed on the bright red fruits:
Sourwood (Oxydendrum arboreum), shown here near Linville Falls off the Blue Ridge Parkway, produces leaves with a deep red color in early fall while the seeds hang down in elegant white sprays, making for a distinctive contrast in colors. Locals make sourwood honey when the trees flower in spring:
Beechdrops (Epifagus virginiana), are nonphotosynthetic parasitic plants that feed off the roots of beech trees. They are common in the fall but often overlooked because they blend in with the forest floor, as these do here at Elk Knob State Park. Claude dePamphilis (click here), now at Penn State University, has shown that this species has a greatly reduced chloroplast genome compared to photosynthetic flowering plants: an example of the ultimate evolutionary dictum – use it or lose it:
This is Chinese sweetgum (Liquidambar formosana) growing on the campus of Appalachian State University in Boone, NC. This ornamental variety and the native species (L. styraciflua) produce leaves showing a variety of colors, ranging from green, to yellow, to orange to red and ultimately to deep purple. Dr. Nicole Hughes and her students at High Point University are studying this phenomenon. Curiously, L. styraciflua, though it ranges from New England to Mexico, is not found in the mountains of western NC.:
Red Maples (Acer rubrum) produce vivid red leaves in the fall. The anthocyanins, which are produced in the fall, may act as a sun shield to protect leaves from excess light when cold. This may allow leaves time to withdraw nutrients back into their twigs for use next spring. William Hamilton, the theoretical evolutionary ecologist, offered an alternative theory in 2001 (click here) that fall leaf colors act as honest warning signal to warn insects to avoid such trees because they are chemically well defended. You can read more about the adaptive significance of fall leaf colors here (click here):
Ginkgo (Ginkgo biloba), as seen here in Boone, NC produce brilliant yellow leaves in the fall, a result of high retention of carotenoids and the production of 6-hydroxykynurenic acid, which only occurs as the leaves turn yellow (click here). This may help disperse excess light energy to protect the leaves, similarly to how anthocyanins do for red leaves. Ginkgos also drop most of their leaves in just one night after a cold snap, the coordination of which is not well understood:
Fall colors surrounding the Linn Cove Viaduct on the eastern flank of Grandfather Mountain, first explored by Andre Michaux in 1794 and later by Asa Gray in 1843. This was the last section of the Blue Ridge Parkway, completed in 1987 because Hugh Morton, who owned Grandfather Mountain, did not want the Parkway to damage the slope, and it took quite a while to design this section. It is now the most popular section of the Parkway:
Sunrise at Beacon Heights rock outcrop along the Blue Ridge Parkway, just east of Grandfather Mountain. In the foreground is the Wilson Creek Area, which is part of the Wild and Scenic River System, while the Linville Gorge Wilderness Area is adjacent to the south:
