Toxicological trivia from may 21, 2014:  Nettle is the common name for plants of the genus Urtica in the family Urticaceae all characterized by having  stinging hairs called trichomes on the leaves and stems, which act like hypodermic needles, injecting histamine and other chemicals that produce a stinging sensation when contacted by humans and other animals. It is one of the common "weeds", well known for its stinging qualities. It is a plant that has other  medicinal applications. It was attributed properties, such as: a) An adjuvant remedy in the treatment of arthritis in Germany; b) In disorders of the kidneys and urinary tract, gastrointestinal tract, locomotor system, skin, cardio-vascular system, hemorrhage, flu, rheumatism and gout;  c) All the above uses are correct. 

Correct answer: c. Read more in Spanish: Nettle. Also in WP: Urtica dioica