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[3] and coarsely textured pairs of leaves, often with striking patterns or variegation. They produce double-lipped flowers in a wide range of colours.[4]
Taxonomy
In volume 2 of Species Plantarum published in 1753, the Swedish botanist Carl Linnaeus established genusLamium by recognizing four species: Lamium album, Lamium purpureum, Lamium amplexicaule, and Lamium multifidum.[5][6] The name LamiumL. is the primary generic name in use today.[2][7]
Lamium album L. – (white dead-nettle) – widespread across Europe + northern Asia from Spain + Norway to Japan + Kamchatka; naturalised in New Zealand + North America
Lamium amplexicaule L. – (henbit dead-nettle) – widespread across Europe and northern Asia from Spain + Norway to Japan + Kamchatka, as well as North Africa, Ethiopia, Azores, Madeira, Canary Islands; naturalised in New Zealand, Hawaii, South America + North America
Lamium galeobdolon (L.) L. – (yellow archangel) – northern + central Europe and western Asia from Spain + Denmark east to Iran + Western Siberia; naturalised in North America, New Zealand, Madeira
Lamium garganicum L. – Mediterranean + western Asia from Portugal to Kazakhstan + Saudi Arabia
Lamium orvala L. – Austria, Italy, Hungary, Slovenia
Lamium purpureum L. (red dead-nettle) – northern + central Europe and western Asia from Spain + Denmark east to Caucasus + Siberia; naturalised in Korea, Taiwan, North America, New Zealand, Argentina, Falkland Islands
The generic name Lamium was used by Pliny the Elder in the first century AD.[8][9] The name comes from the Greek laimos, which means "gullet", a reference to the gaping throat-like appearance of the corolla.[10]
The common name "dead-nettle" has been derived from the German Taubnessel ("deaf nettle", or "nettle without a kernel"),[11] and refers to the resemblance of Lamium album[12] to the very distantly related stinging nettles, but unlike those, they do not have stinging hairs and so are harmless or apparently "dead".
Distribution and habitat
The species are native to Europe, Asia. and northern Africa, but several have become very successful weeds of crop fields and are now widely naturalised across much of the temperate world.[13][14]
Lamium species are widely cultivated as groundcover, and numerous cultivars have been selected for garden use.[4] 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.
^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. ...
DeFelice, Michael S. (2005). "Henbit and the Deadnettles, Lamium spp.: Archangels or Demons?". Weed Technology. 19 (3): 768–774. doi:10.1614/WT-05-072.1. JSTOR3989505.
