Commelinaceae are weeds with unsatisfactory control in different parts of the country. Commelina benghalensis is the main Commelinaceae weed in soybean, corn, coffee and orange crops in Brazil. Commelina diffusa and Commelina erecta are also known as common weeds in national territory. Commelina villosa is only related, until this moment, to Bahia and Goiás States and to Distrito Federal, too. The present paper intented to identify and to relate C. villosa as weed in Paraná State crops, where it may have been confused with other Commelina species, mainly C. benghalensis. Samples of C. villosa and C. benghalensis were collected, in Ponta Grossa, Tibagi, Piraí do Sul, Guarapuava, Pato Branco, Francisco Beltrão, Cascavel, Campo Mourão and Londrina cities, from soybean, bean and corn crops. One part of these material was used to make exsicates and the other one was cultivated at Departamento de Botânica of Instituto de Biociências de Botucatu-UNESP. Morphological characters were analysed and these species were confronted. Analysis of variance were used for quantitatives datas. C. villosa was distinguished because it has translucent fillets, bigger (9.76 x 3.26 cm) eliptical or eliptical-narrow leaves without petiole which are dark green with violet spots in the under surface, among others characteristics. The occurrence of C. villosa in Paraná State was related in all that cities unless Campo Mourão and Londrina.
Spideflower; Commelinaceae; Commelina benghalensis