August_2007

Whorled Sunflower
Helianthus verticillatus

The story of this rare sunflower goes back to its discovery in 1892
near Henderson, TN. Two collections were made by S.M. Bain and
over the years the validity of the plant as a true species was argued.
Meanwhile, the original population was destroyed and no other plants
were seen for over 100 years. Then in 1994 a colony was discovered
in Floyd County, GA and a few years later in neighboring Cherokee
County, AL. Scientists were able to validate the plants as indeed a true
species. In 1998 several plants were found in Pinson, TN, not far from
the original site. Finally, two more populations of this federal
endangered species candidate were found in McNairy County last year.
It is hard to imagine this tall, showy sunflower avoiding detection for
so many years. Each plant consists of a clump of several stems that
can be up to 10 feet tall and topped with clusters of 3 inch flowers. This
species can be distinguished by its leaves that occur in whorls of 3 or
4, the only species of Helianthus to do so.