Scientific name"Urtica urens is a herbaceous annual flowering plant species in the nettle family Urticaceae. It is native to Eurasia and it can be found globally as an introduced species. It is reputed to sting more strongly than the Common Nettle/Stinging Nettle. Each stinging hair on U. urens is a tapered, elongated cell, constricted just below the tip, with a bulbous base embedded in the multicellular pedestal. When hit, the tip breaks off and the hair becomes a miniature hypodermic needle that penetrates the skin and injects its irritating chemicals. The tip of the hair is high in silica, but the silica concentration decreases towards the base, where it is replaced by calcium (Thurston and Lersten, 1969). Each hair is 100 µm long and has 10 µg of fluid that contains histamine and acetylcholine." Depite the stinging irritant, the plant is used medicinally for rheumatoidism and as an aphrodisiac (supposedly by Zulu groups(Watt and Breyer-Brandwijk, 1932)), to make beer, high protein soup and tea.
Emergence of new plants is encouraged by soil disturbance but soil disturbance depletes the seedbank to less than 10% after six years. Seedbanks can otherwise last from 20 to 100 years. After soil disturbance, follow up by weeding emerging plants and plant up the disturbed soil to precvent re-establishment. Remove only with gloves and arms covered to avoid the stinging skin irritant.
This species is a difficult weed in our Fynbos patches. Can you help us remove it? See our activity calendar for upcoming activities, or arrange with us visit our Fynbos patches and do the weeding in your own time.
This species was selected because it is a difficult alien invasive weed in our Fynbos patch(es).