Description: This native perennial plant is about 2-4' tall and either branched or unbranched. The stems are light to medium green and abundantly covered with stiff white hairs that have the capacity to sting when they are rubbed against. The alternate leaves are up to 6" long and 4" across; they are medium to dark green, ovate-cordate to ovate, and coarsely serrated. Young leaves are densely hairy and wrinkled in appearance, while older leaves become less hairy and wrinkled with age. There are 3 prominent veins toward the base of each leaf blade. The petioles are up to 4" long and abundantly covered with stinging hairs, like the stems. The leaf blades may have a few stinging hairs as well.
Individual plants are monoecious
(separate male and female flowers on the same plant) or unisexual. The male
flowers occur in branching cymes from the axils of the leaves. These cymes
spread outward from the stem and they are about the same length as the petioles
of the leaves. Each male flower is greenish white to white and less than 1/8"
across, consisting of 5 narrow sepals, 5 stamens, and no petals. The female
flowers occur in branching cymes toward the apex of the plant. These cymes are
erect to spreading and 4" or more in length. Each female flower is more or less
green and about 1/8" across, consisting of 4 sepals of unequal size (2 large
and 2 small) and an ovary with a long style. The blooming period usually occurs
during mid- to late summer. The flowers are wind-pollinated. Each female flower
is replaced by a small dry fruit that is curved and ovoid in shape. This plant
often forms colonies of variable size.
Cultivation: The preference is partial sun to medium
shade, moist conditions, and a fertile loamy soil with abundant organic matter.
Because of its stinging hairs and tendency to spread, this is a plant that you
would probably not want to plant near the house, except possibly as a privacy
barrier.
Range &
Habitat: The Wood Nettle is common in central and northern Illinois,
but uncommon or absent in parts of southern Illinois (see
Distribution
Map). Habitats include moist floodplain woodlands, mesic woodlands, shady
seeps, and other moist places in wooded areas. Various deciduous trees (e.g.,
elms, maples, or sycamore) dominate the habitats where the Wood Nettle
occurs.
Faunal Associations: The
caterpillars of the following butterflies feed on the foliage: Polygonia
comma (Comma), Polygonia interrogationis (Question Mark), and
Vanessa atalanta (Red Admiral). White-Tailed Deer also graze on the
foliage of Wood Nettle occasionally, notwithstanding the stinging hairs. When
this plant forms dense colonies in wooded areas, it provides valuable cover for
wildlife.
Photographic Location: A
floodplain woodland in Vermillion County, Illinois. The Wood Nettle in the
photographs wasn't in bloom. The plant with narrow leaves on the lower- to
middle-right of the lower photograph is Galium aparine
(Cleavers).
Comments: This native
plant is often mistaken for the introduced Urtica dioica (Stinging
Nettle). Both species have stinging hairs and a similar appearance. However,
the Wood Nettle has alternate leaves, while Stinging Nettle has pairs of
opposite leaves along its stems. There are also differences in the
characteristics of their flowers. Another similar species, Boehmeria
cylindrica (False Nettle), also has opposite leaves, but it lacks stinging
hairs altogether. Like other members of the Nettle family, the Wood Nettle
lacks showy flowers because they are wind-pollinated, rather than pollinated by
insects. Some people may regard this species as an undesirable woodland weed
because of its stinging hairs and unassuming appearance, but it has some
ecological value as indicated above.