Prairie Wanderings: Stinging nettles along Cedar Creek
By PAUL G. JANTZEN
Contributing writer
Where Cedar Creek empties into the Cottonwood River, the creek is lined with large trees: sycamores, elms, bur oaks, and green ash. In more open areas are scattered honey locusts, black willows, hackberries, and a colony of false indigo. The forest understory is dense with nettles and further out are occasional woodland ruellia, golden zizia, pokeberry, poison ivy, and violets.
The dense population of stinging nettles is of special interest. Found in most of the Great Plains, they are 0.7 to 1.3 meters tall (27-51 inches). They have inconspicuous, greenish flowers from late June until October, the male and female flowers usually borne on separate plants. (The species name is dioica, meaning "two house.") Pollination is accomplished by visiting beetles and hover flies but more importantly by mechanically throwing pollen into the air whose currents disperse the pollen. In the bud stage of the male flowers, the stamens are bent inward, holding the pollen-loaded anthers in place. When the bud opens, the released stamens thrust the anthers outward to discharge their pollen into the wind. In those individual plants that have both male and female flowers, the male flowers mature earlier, thus avoiding self — pollination.
Perhaps of greater interest is the nettle's means of defense against plant eaters. The stinging sensation I experience when handling the plant is also felt by other creatures such as rabbits poking around with their sensitive noses. (The genus name is Urtica, from ura, meaning "to burn.") The secret is found in the hollow stinging hairs scattered over the leaves and stems. Each hair has a tiny tip that easily breaks off when touched. The broken edges of the hair are sharp and can cut human skin. A poison stored in a small chamber at the base of the hair is discharged into the wounded skin. The venom contains formic acid which causes pain. The associated histamine causes the swelling of tissue. One such experience teaches animals (except biologists) to leave the nettle alone.
There are exceptions: nettles are the favorite food of the common red admiral butterfly. The female even selects nettle leaves on which to lay her eggs. When the young hatch, the caterpillars chew leaf tissue between the poison hairs, avoiding contact with them.
Euell Gibbons reports that the sting of nettles can be relieved by rubbing the affected area with the juicy leaves of curly dock.
Various parts of this nettle have been used for centuries in Europe and Asia for food, thread, and medicine. The young leaves were cooked which destroyed their stinging properties. They are good sources of vitamins A and C, protein, and several minerals. Stem fibers were used as thread in making a durable cloth. Chronic rheumatism was treated by flogging the affected body part with stinging nettles. Juices pressed from the leaves were used to control nose bleeding. And a decoction of the nettle leaves and roots was used to treat internal bleeding.
The stinging nettle was naturalized in America from Europe.
