Urtica dioica

Common Nettle

Scientific name: Urtica dioica L.

Diagnostic features
Strongly rhizomatous and/or stoloniferous usually dioecious perennial to 2m or even more.
Leaves and stems usually with abundant stinging hairs and more numerous smaller non-stinging hairs.
Terminal leaf-tooth longer than adjacent laterals.

Habitat
Native.

This species is keyed out at Page 2512: Urtica (Urticaceae) in the Text Key.

Note
Very variable, especially in leaf-shape and pubescence; stingless, subglabrous and monoecious variants are known.

The 2 subspecies apparently do not differ constantly in morphology or chromosome number, and may form fertile hybrids; intermediates occur.

Key to the subspecies:
a. Plant with conspicuous stinging hairs at least on leaf upperside; non-stinging hairs relatively coarse and sparse, c.25-35 microns across at base; lowest flowering node 7th-14th from base.
....................................... Urtica dioica dioica.
b. Plant without stinging hairs; non-stinging hairs relatively fine and dense, c.20-25 microns across at base; lowest flowering node 13th-22nd from base.
.......................... Urtica dioica galeopsifolia.

The 2 subspecies apparently do not differ constantly in morphology or chromosome number, and may form fertile hybrids; intermediates occur.

Kingdom Plantae
Phylum Angiospermophyta
Class Magnoliopsida
Subclass Magnoliidae
Superorder Hamameliflorae
Order Urticales
Family Urticaceae
Genus Urtica
Species Urtica dioica

Urtica dioica L.

Common Nettle (English)
Nettle, Common [English]

Urtica dioica 3 (Flowering habit, picture taken in the Netherlands, in slide collection of NHN-Leiden)
Urtica dioica 4 (Flowering habit, picture taken in the Netherlands, in slide collection of NHN-Leiden)
Urtica dioica a (Leaf, drawing by H. Thompson in Stace, 1997)
Urtica dioica dioica 5 (Flowering habit, male, picture taken in S Somerset by C.A. Stace)
Urtica dioica dioica 6 (Flowering habit, female, picture taken in S Somerset by C.A. Stace)
Urtica dioica galeopsifolia 2 (Flowering habit, picture taken in Berks by A. Showler)