The Original Mystery Plant

Answer to this week's mystery plant

The mystery plant is a small tree, which is native to the Far East, but has been introduced widely in the United States. It is now naturalized commonly in many places.

It is a woody weed in the South and is often found on roadsides, vacant lots, or river bottoms. The trees have extremely variable leaves, which may be heart- shaped to nearly roundish or oblong, almost always with a point at the tip.

Leaves of young plants and sprouts may be deeply lobed. The margins of the leaves are sharply toothy, and the upper surface of the blade is generally smooth and not too hairy. This species has a very close relative, nearly a dead- ringer, but its leaves are more hairy and a bit scratchy above.

The flowers are unisexual and always held together in short spikes. Each female flower within its spike ends up having its tissues fused together with a neighboring flower, and the resulting fruit is what we a multiple fruit, architecturally similar to what happens with a pineapple. The fruits are luscious and juicy and at maturity may be white or pink, or even red.

This tree figures prominently into the economic history of the American South, and in the late 17th Century a fledgling silk industry began. Of course, silk comes from silk worms, and silk worms love to eat the leaves of our Mystery Plant. Unfortunately for the silk industry, the worms are extremely finicky and usually very hungry and hard to care for.

The American silk industry was not a real challenger to the enormous economic power realized from timbering and later from the development of rice as a commercial crop. However, the trees continue to pop up here and there, often as a result of their popularity with their feathered friends.

The tree was officially named by Charles Linnaeus in 1753. Linnaeus from Sweden was something of a genius and truly one of the world's greatest naturalists. He is known as the Father of Plant Taxonomy and was responsible, in large part, for the standardization of binomial naming.

Before his time, botanists came up with cumbersome, wordy descriptions of plants and when printed actually ended up being the plant's name.

Since Linnaeus's time, scientists have consistently stuck with this process. In fact, it was Linnaeus who championed the usage of herbaria or collections of dried plant specimens as the best way of studying plant taxonomy instead of relying on inaccurate copies of plant illustrations that had ended up in all of the books.

[Answer: "White mulberry," Morus alba]

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