Great Smoky Mountains National Park is renowned for its variety of wildflowers. Over 1,500 species grow in the Smokies, more than in any other North American national park. North of the Tropics, only China rivals the southern Appalachians for plant diversity.
Why such a wondrous diversity in the Smokies? Mountains, glaciers, and weather are the big reasons. The Great Smoky Mountains provide a range of elevations in the park from 875 to 6,643 feet. This altitudinal range mimics the latitudinal gamut you would experience driving from Georgia to Maine. Wildflowers typical of the South, like sweet pine sap, live in the lowlands of the Smokies, while such northern species as bluebead lily and grass-of-Parnassus find suitable habitat at the higher elevations.
By their form, mountains also provide a variety of slopes and aspects. The habitat on a sunny, dry, south-facing ridge is very different from that on a cool, moist, northern slope, even if the two are at the same elevation. Higher mountains also shade lower ones, creating even greater habitat variety.
The absence of glaciation has also affected species diversity in the Smoky Mountains. During the last ice age, say 10,000 years ago, glaciers scoured much of North America but did not quite reach as far south as the Smokies. Consequently, these mountains became a refuge for many species of northern plants and animals that were disrupted from their homes. The Smokies have, in fact, been mostly undisturbed by glaciers or ocean inundation for over a million years, affording species time to diversify.
In terms of weather, the park’s abundant rainfall and high summertime humidity provide excellent growing conditions for a wide variety of plants. In the Smokies, the average annual rainfall varies from approximately 55 inches in the valleys to over 85 inches on some peaks. During summer, the relative humidity in the park is about twice that of the Rocky Mountain region. Wildflowers in the Great Smoky Mountains also have the luxury of a relatively long growing season.
Each season Great Smoky Mountains Association volunteers produce a Wildflower Watching Report for our members. Find it HERE.