False Nettle
Boehmeria cylindrica
Nettle family (Urticaceae)

Description: This perennial plant is about 2-3' tall, branching occasionally. This member of the Nettle family lacks stinging hairs. The stems are light green, 4-angled or round, and glabrous or slightly pubescent. The leaves are usually opposite along the stems, but sometimes they are alternate. They are ovate or ovate-lanceolate, up to 4" long and 2" across, and have long slender petioles. The upper surface of each leaf is dark green (in the shade) and glabrous or slightly pubescent; a central vein and 2 parallel secondary veins are readily observable. The margins are coarsely serrated. Spikes of green or greenish white flowers appear from the axils of the upper leaves. They are straight and angle upward from the axis of the central stem. The flowering spikes are about –3" long; sometimes they are terminal, but more often they will develop additional leaves beyond the flowers. False Nettle is usually dioecious, with male and female flowers produced on separate plants. Male flowers are distributed along the spikes in bunches, while female flowers are produced along the spikes more or less continuously. These flowers are very small and lack petals. Each male flower has a 4-parted calyx and 4 stamens, while the calyx of the female flower is tubular with 2-4 teeth. The blooming period is mid-summer to early fall, and lasts about 1-2 months. There is no floral scent; pollination is by wind. The fruit consists of a small achene. This description applies to the typical woodland variety of False Nettle, Boehmeria cylindrica cylindrica. The other variety of False Nettle, Boehmeria cylindrica drummondiana, grows in the sun and has a somewhat different appearance.

Cultivation: The preference is light shade, moist conditions, and rich loamy soil. In sunnier locations, this plant prefers wetter ground and the foliage may become yellowish green.

Range & Habitat: The native False Nettle is a common plant that occurs in most counties of Illinois (see Distribution Map). Habitats include wet to mesic deciduous woodlands, especially in floodplain and bottomland areas, as well as various wetlands, including swamps, low areas along rivers, borders of small streams, seeps, and sandy marshes. False Nettle can be found in both degraded and higher quality habitats.

Faunal Associations: The flowers don't attact many insects because they are wind-pollinated. Caterpillars of the butterflies Polygonia comma (Comma), Polygonia interrogationis (Question Mark), and Vanessa atalanta (Red Admiral) feed on the foliage of False Nettle; caterpillars of the moth Bomolocha manalis (Flowing-Line Bomolocha) also feed on this plant (Wagner, 2005; Bouseman & Sternburg, 2001). Larvae of a fly, Neolasioptera boehmeriae, form spindle-shaped galls on the stems. Because the foliage lacks stinging hairs and it is non-toxic, mammalian herbivores probably browse on this plant occasionally.

Photographic Location: Along a woodland path at Busey Woods in Urbana, Illinois.

Comments: Sometimes people instinctively shy away from this plant thinking that it has stinging hairs – in fact, this is not the case, hence the common name. In Illinois, the two members of the Nettle family with stinging hairs are Laportea canadensis (Wood Nettle) and Urtica dioica (Stinging Nettle). The latter species has been introduced from Europe. The other common member of the Nettle family without stinging hairs, Pilea pumila (Clearweed), is a hairless annual plant with translucent stems and shiny leaves. Clearweed has terminal flowering spikes that are usually shorter than the petioles of the leaves, while the flowering spikes of False Nettle are usually longer than the petioles, and leaves are often produced beyond the flowers.