Plants of the Eloise Butler Wildflower Garden

Nettles have small greenish flowers in branching clusters (cymes) that form from the upper leaf axils. Wood Nettle is a native erect perennial growing to 4 feet in height on green stems that are densely to sparsely covered with bristly stinging hairs and non-glandular non-stinging hairs. The plant can be invasive.

The leaves are alternate (the only such nettle), long-stalked, widely oval with coarse teeth. The very upper leaves can be opposite. The upper leaf surface is dark green with a main midrib vein, parallel laterals curving upward from the midrib and a crinkled looking pinnate vein pattern between them; the underside may have some longer stinging hair on the veins and is much paler in color due to fine surface hair. The leaf base can be rounded, truncate or wedge shaped, but without auricles.

The inflorescence consists of a panicle of long stalked clusters (cymes) of small female flowers (pistillate) in the upper leaf axils and clusters of male flowers (staminate) from the lower leaf axils. These are on the same plant and are held somewhat horizontal to the stem. The clusters have a creamy color before flower opening.

The sexes of the flowers are on separate panicles and the sepals and petals have combined into what are called tepals. Male flowers have 5 tepals, equal in length with 5 stamens placed opposite the tepals with their filaments slightly longer than the tepals. There is a false pistil in the center. The female flowers have 2 to 4 tepals in pairs, where the outer pair is either very short or entirely absent, the inner pair no longer than the ovary which is globose in shape. There is a long single style that has a feathery appearance from the stigma extending along the style.

Seed: Pollination is by the wind, resulting in the fertile female flowers producing a dark partially circular achene that is not enclosed in a capsule or entirely by the perianth of the flower.

 

Habitat: Wood Nettle grows from a rhizomatous root system with tuberous roots that allows it to spread vegetatively and form colonies. It prefers rich moist soils with partial sun in forests, along stream edges and marsh edges. At Eloise Butler you can find it along the back fence and on the wetland path and nearby is the Stinging Nettle.

Names: The genus name Laportea is named for Francois Louis de Laporte, Count of Castelnau, (1810-1880) a widely traveled Entomologist of the 19th century who traveled and collected in the United States between 1843 and 1847; and of course, canadensis is for "of Canada," where the plant was originally described. Leportea is a small genus - 22 species worldwide and 2 in North America - all with alternate leaves and the flower description similar to that described above.

The common name “Nettle” may be from the Anglo-Saxon and Dutch word “Netel”, that work being derived from “Noedl”, a needle. There is also speculation that it comes from much older words that refer to the ability of the fibers to be sewn, a process used widely with the nettle species Urtica dioica.

The author names for the plant classification are: First to classify in 1753 using the name Urtica canadensis was '(L.)' which refers to Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy. His work was amended in 1854 by ‘Wedd.’, which refers to Hugh Algernon Weddell (1819-1877) English born French physician and botanist who specialized in South American flora.

Comparison: The Stinging Nettle, Urtica dioica, has opposite more lance-like leaves, is taller, and has a different looking flower cluster - more narrowly elongated and drooping. See comparison drawings below in the photos. The other Nettle in the Garden that resembles Wood Nettle is the stingless Canadian Clearweed, Pilea pumila. The other species of Laportea in North America, Laportea aestuans, is found only at the southern tip of Florida. It has stipitate-glandular hairs in addition to stinging hairs and the achenes are smaller.