3. Oak Circle

Caucasian Wingnut (Pterocarya fraxinifolia)

Elbow Room

This wingnut species originated in the Caucasus and northern Iran and was transported to Europe in 1782 by the French botanist and statesman André Michaux. The tree was greatly valued for its fast growth and its impressive branch spread, which offers excellent shade. Capable of reaching 80 feet in height and 70 feet in branch spread, this tree excels in parks and public gardens but is too hefty for the average backyard. The Caucasian wingnut's branches can attain such a length and weight that they need a little propping up.

In 1978, BBG arborists propagated the Caucasian wingnut. This photo shows the healthy offspring—now nearly 30 years old—in early spring before its leaves have emerged. (Photo by Romi Ige)

Cloning Around

Botanic gardens are living museums: They hold valuable collections of a wide range of specimens. But unlike paintings, sculptures, or fossil collections, plants have a life span and will eventually die. One way BBG perpetuates its collection is through asexual propagation, sometimes called cloning. Cloning trees is much easier than cloning, say, sheep. Arborists take a cutting from a branch of the parent tree, and then propagators follow one of several methods for rooting it. This Caucasian wingnut, which is on the Great Trees of Long Island list, was propagated in 1978.

Notable Neighbors:

• 3A. Scarlet oak (Quercus coccinea)
• 3B. White oak (Quercus alba)
• 3C. Weeping beech (Fagus sylvatica 'Pendula')
• 3D. Persian ironwood (Parrotia persica)

"Wingnut" may sound like a fun nickname for your friends, but it actually refers to the winglike shape of this tree's fruit, shown here. (Photo by Medi Blum)

Because of his botanical expertise, André Michaux was originally chosen by President Thomas Jefferson "to find the shortest and most convenient route of communication between the United States and the Pacific Ocean." Michaux made it only as far as the Ohio River Valley, but Jefferson's project was soon completed by Meriwether Lewis and William Clark.