Weeding the nettles I: Clarifying species limits in perennial, rhizomatous Urtica (Urticaceae) from southern and central Chile and Argentina. Weigend, Maximilian Luebert, Federico Phytotaxa 2009 2009-12-31 2 1 12 5LPXQ 1435599 Linnaeus (1753: 984) subsp. dioica Linnaeus 1753 [183,830,227,256] Magnoliopsida Urticaceae Urtica Plantae Rosales 6 7 Tracheophyta subSpecies dioica dioica   Lectotype(designated by Woodland, 1982: 283): anon., Herb. Linnaeus 1111.8(LINN!, photographs: AUB, DAO, MTMG). — Fig. 1 A.   Urtica dioicasubsp. dioicais a widespread nitrophilous weed, common throughout Europe, western Asia, northern Africa and eastern North America. It is also found on several islands in the North Atlantic (e.g., Iceland). The typical subspecies is here reported for the first time from South America, probably from introduced populations. It can be readily differentiated from the native species by its very dense pubescence of stinging hairs on the abaxial leaf veins, its usually much wider and more triangular leaves (in the weedy form foundin South America) and its predominantly dioecious populations. Numerous monoecious individuals of  U. dioicasubsp. dioicahave been reported, but these always make up only individual clones in a population, with the bulk of individuals unisexual (Heemskerk et al.1998). So far, monoecious individuals have not been reported from South America.  Urtica dioicasubsp. dioicais likely much more common in southern South America than is reflected by the number of specimens studied, as botanists may refrain from collecting it, recognizing it as an introduced weed. It is likely to be locally common in pastures and on road sides in southern and central Chileand Argentina.   Representative specimens:   ARGENTINA:  Prov. Córdoba, Depto. Río Segundo, Río Segundo, en “Las Compuertas”,  13.11.1970,  R. Subilis1084(sterile, MO).   CHILE: VIII Región, Bío-Bío: Prov. Concepción, Río Bío-Bíoestuary,  30 m, 36º49' S, 73º10' W,  23.08.1968,  C. W. O´Briens.n.(male, CONC).   IX Región, Araucanía: Prov. Cautín, Villarica,  220 m,  Jan 1962, G. MonteroO. 6531(female, CONC).  XIV Región, de Los Ríos: Prov. Valdivia, Valdivia, Isla Teja,  70 m,  Dec. 1961, H. Gunckel38.813(female, CONC). 1970-11-13 MO R. Subilis Argentina Prov. Rio Segundo Rio Segundo 6 7 1 Cordoba 1968-08-23 CONC C. W. O'Brien Chile Region 30 -36.816666 Rio Bio-Bio 1185 -73.166664 Prov. Concepcion 6 7 1 Biobio 1962-01 CONC IX Region & Montero Chile 220 Villarica Prov. Cautin 6 7 1 Araucania 1961-12 CONC Gunckel Chile Region 70 Valdivia Prov. Valdivia 6 7 1 Los Rios