The smells of autumnWritten by George Ellison
Fall is the odiferous time of the year.
I don’t possess a very discriminating sense of smell, but certain fragrances arise in the natural world this time of the year that even I can detect.
Have you ever been walking a mountain trail in October when you encountered a musky smell that reminded you of skunk or scat? Thus alerted, I consider five possible sources: skunk, bear scat, wild boar, skunk goldenrod, and galax.
The first three are self-evident, more or less — although we will return in the end to skunks — which always deserve the last word when it comes to odiferousness of any sort.
A note titled “Wild Ideas: The Odor of Galax” by J. Amoroso that appeared in Chinquapin: The Newsletter of the Southern Appalachian Botanical Society in 2000, reviewed speculations by several botanists about the possible causes for the peculiar smells associated with this well-known plant.
According to Amoroso, the source of the odor is still unknown but “Speculation has linked it to chemical compounds-long sulfur chains such as mercaptan or butyl-thiols (which are similar to the chemicals found in a skunk’s scent) emitted from the stomata or from the decomposing leaves.”
In other words, crushed living galax leaves produce no smell — but sulphur compounds could be released as the older leaves decompose.
If you’re in the higher elevations, say at Waterrock Knob, a very similar odor will often be emanating from a nearby stand of skunk goldenrod (S. glomerata), a species easily recognized by its large basal leaves. The plant is found only in the higher elevations of 13 mountain counties in Tennessee and North Carolina and no place else in the world.
The smell can’t be detected from crushed foliage or flowers. It simply forms a “cloud” over and around a stand of the plant. It seems likely that decaying foliage (or some other aspect of the plant) is emitting decomposed sulfur compounds similar to those exuded by skunks and galax.
Most features associated with plants can be attributed to three tactics: (1) pollinator attraction (flowers), (2) seed distribution (fruits), and (3) protection (thorns, smells, poisonous oils, etc.). It’s likely that the sulpheric emanations of galax and skunk goldenrod are related to either the first or the third categories.
“Skunk” and “odor” are synonymous. You cannot hear or read the word skunk without thinking of odor. Five species are resident in the United States: hooded, hog-nosed, western spotted, eastern spotted, and striped. Only the last two reside in the Smokies region.
The striped skunk — which is black with two white stripes running up its back to form a cap on top of its head — is the one that usually comes to mind when someone starts telling skunk tales in this neck of the woods.
The spotted skunk is, in my experience, more common in the higher elevations. Sometimes referred to as a civet, it is black with a white spot on its forehead and under each ear. There are also four broken white stripes along its neck, back, and sides, as well as a white-tipped tail.
Now we get to the interesting part. When provoked, a striped skunk simply raises its tail daintily like a plume and assumes a U-shaped posture that allows its hip muscles to squeeze the odiferous fluids indiscriminately out of its anal glands.
The spotted skunk has perfected that basic strategy. When frightened or angered, it will often do a “handstand” on it front feet. This posture allows the critter to look between its legs and see where to aim the spray.
These random musings will perhaps give you something to think about the next time you’re out walking in the fall of the year and smell a sulpherous smell.