Forest Preserve District of Cook County (Illinois)
Nature Bulletin No. 426-A September 25, 1971
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation
****:NETTLES
People don't seem to get it through their heads that they should be
appropriately clothed when they visit our forest preserves and expect to
enjoy a walk through the woodlands. Woolens, tweeds, or soft-textured
garments will be covered with burs, stick-tights and "begger Lice".
Denims are perfect. Bare-legged people will suffer not only from
mosquitoes, flies, thorns, briars, and possible poison ivy, but also from
the stings of nettles.
Alistaire Cooke, writing about the American summer, said that out of
ten people he polled, only three had even a remote idea of what a nettle
is, It is a plant you seldom notice but you sure feel it, particularly
among the luxuriant waist-high undergrowth in woodlands on rich black
moist soil.
Wading through this vegetation, you may experience a stinging burning
sensation on your legs and arms but it's hard to find the miscreant
because its poison is not felt immediately. That poison contains the
formic acid also present in the stings of bees and ants. The quickest
relief is obtained by mashing the leaves of sourdock or other acid plant
into a pulp and smearing that over your skin. The slimy juice of the
jewelweed is another remedy.
The stinging nettle has thousands of poison-loaded hairs which
antedated, by millions of years, the hypodermic needle and syringe
invented by a French physician in 1853. These hairs are tiny hollow
tubes stiffened with silica and lime taken from the soil. Their curved
tips are closed but the walls are very thin and snap off, when touched,
leaving a sharp slanting point which easily punctures your skin. At the
base of the hair is a soft bulb containing a poison which is squirted out
by the same pressure which snapped off the point when you brushed the
hair.
That burning sensation, caused by our common nettles, lasts only about
20 minutes and is not serious but some of the tropical species are far
more dangerous. Their stings vary in severity from those produced by
bees and wasps to what happens when bit by a venomous snake. One
nettle, on Timor, causes a condition like lockjaw which may last for
weeks or months. Another, in Java, is frequently fatal.
The Nettle Family -- and this is surprising -- includes the elms,
hackberries, mulberries, osage orange, hops and Indian hemp or
marijuana. However, in America, the true nettles are all herbs with elm-
like leaves. They range in height up to several feet but are quite
variable. Some are perennials and some are annuals; some have
opposite leaves but others have alternate leaves; some have those pesky
stinging hairs but some do not. Nearly every part of the United States
has one or more kinds of nettles and the Chicago region has four, two of
which are common.
Few of you who read this are botanists. It would be difficult and foolish
to name, described and distinguish between the different kinds of
nettles and plants that are called nettles. Some of the latter belong to the
Mint Family; others belong to the Nightshade Family which includes
the "Irish" potato. In fact, one of the so-called nettles -- really a
nightshade -- was the original food of the devastating potato beetle.
The Indians and the Europeans have many uses for nettles. In spring,
the young shoots are used like spinach greens or boiled in soup.
Medicines for various ailments are concocted from parts of nettles.
They used to be one of the most important sources of fiber for sewing
and for weaving coarse linen.
Remember this, when you do run into them: don't worry about it.
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