white nettle flowers.
 purple nettle flowers.
 yellowish nettle flowers.
 light purple nettle flowers.

L., 1753
 (Information from  Wikipedia) : Nettles constitute between 24 and 39 species of flowering plants of the genus Urtica in the family Urticaceae, with acosmopolitan though mainly temperate distribution. They are mostly herbaceous perennial plants, but some are annual and a few are shrubby. Most of the species have stinging hairs on the stems and leaves.
The most prominent member of the genus is the stinging nettle,Urtica dioica, native to EuropeAfricaAsia, and North America. The genus also contains a number of other species with similar properties, listed below. However, a large number of species included within this genus in the older literature are now recognized as synonyms of Urtica dioica. Some of these taxaare still recognized as subspecies.
Urtica nettles are food for the caterpillars of numerousLepidoptera (butterflies and moths), such as the tortrix mothSyricoris lacunana and several Nymphalidae.