Galeopsis tetrahit, Galeopsis carthusianorum, SE: Pipdån, röddån,
DE: Gemeine Hohlzahn, Stechender Hohlzahn,
NL: Gewone hennepnetel, UK: Common Hemp Nettle

Scientific name:		Galeopsis tetrahit L.
Synonym name:		Galeopsis carthusianorum auct.(more authors)
Swedish name:		Pipdån, röddån
German name:		Gemeine Hohlzahn, Gewöhnlicher Hohlzahn, Stechender Hohlzahn, Stacheliger Hohlzahn, Hanfnessel
Nederlandse naam:		Gewone hennepnetel
English name:		Common Hemp Nettle
Plant Family:		Lamiaceae, Mint family, Kransblommiga växter

Life form:		Annual
Stems:		Dense spreading hairs; stem swollen at the leaf-junctions; square in cross section
Leaves:		Opposite, stalked. Blade ovate, with a long tapering point, smooth-hairy, margins with large teeth; lowest lobe of flower not or scarcely notched and the dark lines on it not reaching the margin.
Flowers:		HermaphroditePurple, mauve or white, but not yellow (except in centre).Corolla is tubular
Flowering Period:		July, August, September
Fruits:		A four-parted schizocarp. Mericarp oval, slightly flattened, brown.
Habitat:		Throughout the country, but more sparingly in the mountains; farmland, settlements

Derivation of the botanical name: Galeopsis, from a Latin name used by Pliny for some nettle-like plant. tetrahit, Greek tetra (four) and hitus (circumference), the name may refer to the square stem. carthusianorum, of the monks of the Carthusian Monastery of grande Chartreuse near grenoble, France. The standard author abbreviation L. is used to indicate Carl Linnaeus (1707 – 1778), a Swedish botanist, physician, and zoologist, the father of modern taxonomy. Galeopsis tetrahit are pollinated by Self.The plant is self-fertile. Galeopsis species are very rough to the touch whereas the Lamium species (Dead-nettles) are very soft.