Photo by John Nelson in Florence, SC Autumn has once again snuck up on us, as it always does.

Autumn is known mostly as a time of cooling temperatures and falling, colorful leaves. Shorter day lengths (since June 21) have had plenty of biological ramifications on the plants and animals around us. In the Southeast, one can hardly go through the fall without marveling at the display of asters and goldenrods, besides the change of leaf color. The change of color in fall leaves is often thought to be a result of cool temperatures or even frost. However, the marvelous fall color of deciduous trees in the upcountry of the Smoky Mountains, and elsewhere in the Appalachians, begins well before frost has occurred.

The mystery plant has come into its own since the tail–end of summer. It is often seen along the Atlantic coast, where it has naturalized.

It is not a native plant to the South. It is actually from South America, mostly Argentina and Uruguay, but it has been grown as a garden plant for at least a couple hundred years both in the US and in Europe. In our area, from NC down through TX, it has naturalized from original garden plantings and now behaves as something of a native species. Naturalized species are often quite a problem now, being introduced from one place, and then acting as a regular part of the landscape. Japanese honeysuckle, kudzu, and beach vitex are good examples.

Photo by John Nelson Our mystery plant remains a popular garden plant, and it is easy to grow. It is especially good as a rock garden addition. Where it has naturalized, it doesn’t seem to pose an invasive problem, so much as a delightful and autumnal curiosity, often on roadsides, ditch edges, or at old home sites.

It grows from a bulb, as do many of its relatives such as amaryllis and hurricane lily. Each plant will produce a shock of slick, bright green, narrow leaves, with the leafless flowering stems up to about 6” high. The sepals and petals (three each) make up the perianth, which is brilliant white (the scientific name alludes to this…and brings to mind clear, brilliant, and innocent.)

It is very closely related to various southeastern species which are indeed native to our area, and go by the name of Atamasco, or zephyr lily. These natives bloom in the spring.

Answer to last week’s mystery plant

Elephant ears, (left) Alocasia macrorhiza,

(right) Colocasia esculenta

Dr. John Nelson is the curator of the USC Herbarium.

To learn more about the Herbarium, call him at

777-8196. His department also offers free plant identification.

www.herbarium.org