Urtica, Linnaeus, 1753

Weigend, Maximilian & Luebert, Federico, 2009, Weeding the nettles I: Clarifying species limits in perennial, rhizomatous Urtica (Urticaceae) from southern and central Chile and Argentina., Phytotaxa 2, pp. 1-12 : 6

Key to perennial rhizomatous species of Urtica present in Chile and Argentina

1 Dioecious plants (i.e., male or female clones, each clone and each aerial shoot only with one sex, rarely monoecious); achenes ovate in outline, widest below the middle; plants (stem and leaves abaxially and adaxially) densely setose, stem often flushed red .................................................................................................................... Urtica dioica

- Monoecious plants; achenes subcircular in outline, widest in the middle; plants (stem and leaves abaxially and adaxially) variously setose, often sparsely so, stem green or whitish, not flushed with red ............................................... 2

2 Stems densely pubescenct, white or grey, setose; abaxial leaf surface densely setose; adaxial leaf surface densely pubescent, white or grey ............................................................................................................................ Urtica mollis

- Stems sparsely pubescent, light green, esetulose or sparsely setose; abaxial leaf surface esetulose or sparsely setose; adaxial leaf surface sparsely pubescent, light green .................................................................................................... 3

3 Fruiting perianth without stinging hairs ......................................................................................... Urtica magellanica

- Fruiting perianth with 1 or 2 stinging hairs on the midvein of larger lobes .................................................................. ....................................................................................................... Urtica lilloi (see discussion under U. magellanica )