The Original Mystery Plant

Photo by John Nelson

The mystery plant is very tiny compared to its various taller and flashier relatives. Its leaves are puny and bract- like. Its flowers, while pretty, are so small you have to get on your hands and knees to see them. The mystery plant has developed a complex, a species complex.

Botanists refer to a species complex as a group of closely related species that are difficult to distinguish as individual units and hybridize with each other if growing together often resulting in complicated but very interesting genetics.

The members of a species complex are often hard to precisely evaluate. Their naming also ends up being something of a problem, sometimes a big problem. Usually, the identified members of a species complex have had more than one scientific name applied to them, which, of course, is a botanical no- no.

The mystery plant doesn't get much taller than a foot off the ground, and it's often hidden in the grass. It's related to foxgloves and the garden digitalis, and like them, its flowers exhibit fusion. The five sepals are fused forming a tubular calyx, and the five petals are fused into a tubular corolla.

The corolla is bright pink and softly hairy on the inside protecting four tiny stamens and a pistil. The leaves are narrow and more like scales than regular leaves. The stems are smooth and yellow.

The mystery plant blooms in the fall, and usually only one or two flowers will be open at a time on a single plant. The corolla lasts only one day then falls off. Except for the flowers, which individually are attractive, the whole plant is rather inconspicuous. This particular species occurs in a variety of habitats from New Jersey through Tennessee down to Louisiana and well into central Florida.

The species is the source of serious research by Dr. Maile Neel and her student, Jamie Pettengill, botanists from the University of Maryland.

The research being performed is intensive, which involves carefully measuring the stems, leaves, bracts, flower stalks, and corollas of at least 30 plants in a given population.

Their research is also backed up by molecular studies of the DNA sequences in the leaf tissue. It's a lot of work, but hopefully it will further explain the accurate relationships between the mystery plant and its nearest relatives. Answer to this week's mystery plant [Answer: "Autumn bells," "Little finger-pink," Agalinis obtusifolia]

Dr. John Nelson is the curator of the USC Herbarium. To learn more about the Herbarium, call 777-8196. The

department also offers free plant identification.

www.herbarium.org