|Henbit deadnettle (Lamium amplexicaule)|
About 50 species; see text
Lamium (deadnettle) is a genus of about 40-50 species of flowering plants in the family Lamiaceae, of which it is the type genus. They are all herbaceous plants native to Europe, Asia, and north Africa, but several have become very successful weeds of crop fields and are now widely naturalised across the temperate world.
The genus includes both annual and perennial species; they spread by both seeds and stems rooting as they grow along the ground. They have square stems and coarsely textured pairs of leaves, often with striking patterns or variegation. They produce double-lipped flowers in a wide range of colours.
The common name "deadnettle" refers to the resemblance of Lamium album to the very distantly related stinging nettles, but unlike those, they do not have stinging hairs and so are harmless or apparently "dead".
Lamiums are widely cultivated as groundcover, and numerous cultivars have been selected for garden use. They are frost hardy and grow well in most soils. Flower colour determines planting season and light requirement: white- and purple-coloured flowered species are planted in spring and prefer full sun. The yellow-flowered ones are planted in fall (autumn) and prefer shade. They often have invasive habits and need plenty of room.
Lamium species are used as food plants by the larvae of some Lepidoptera species including Angle Shades, Setaceous Hebrew Character and the Coleophora case-bearers C. ballotella, C. lineolea and C. ochripennella.
- RHS A-Z encyclopedia of garden plants. United Kingdom: Dorling Kindersley. 2008. p. 1136. ISBN 1405332964.
- Brown, V. K.; Lawton, J. H.; Grubb, P. J. (29 August 1991). "Herbivory and the Evolution of Leaf Size and Shape [and Discussion]". Philosophical Transactions of the Royal Society B: Biological Sciences 333 (1267): 265–272. doi:10.1098/rstb.1991.0076. "... appearance of vegetative plants of white dead-nettles (Lamium album) (Labiatae) bear a close resemblance to stinging nettles (Urtica dioica) (Urticaceae). Stinging hairs deter soft-muzzled, grazing mammals, suggesting that dead-nettles are harmless Batesian mimics. However, many other labiates that do not closely mimic nettles have ovate leaves with serrate margins, so if this is a case of true mimicry, it may have involved rather little modification in leaf shape. ..."