Diversity and Distribution of Solanum subg. Leptostemonum in Brazil Maria de Fátima Agra Laboratório de Tecnologia Farmacêutica Universidade Federal da Paraíba João Pessoa, Paraíba Brazil Keywords: Solanaceae, spiny Solanum, South America, jurubeba Abstract Solanum subg. Leptostemonum (Solanaceae) is the second largest subgenus of Solanum, with approximately 450 species. It is of cosmopolitan distribution with its primary center of diversity in South America and secondary centers in Australia and Africa. Morphological characters used to distinguish it from other subgenera include a stellate indument, prickly herbage and attenuate anthers. In Brazil, approximately 455 specific names have been applied to the species of subgenus Leptostemonum, of which 345 are synonyms. Solanum subg. Leptostemonum is represented in Brazil by about 110 species, including undescribed taxa; of these, 58 are endemic (about 53%). They are assigned to the following sections: Acanthophora, Crinitum, Melongena, Erythrotrichum, Herposolanum, Lasiocarpa, Micracantha, Persicariae, Polytrichum and Torva. They are encountered in many kinds of vegetation and display marked adaptations to humid or dry, hot and seasonal habitats. The principal center of diversity and endemism in Brazil is found in the southeastern coastal region, which has about 64 species (representing 58% of the total Brazilian species) and 20 endemics. INTRODUCTION The subgenus Leptostemonum Dunal (Bitter) is the second largest subgenus of Solanum, with approximately 450 species (Whalen, 1984; Nee, 1999) of cosmopolitan distribution. The primary center of diversity of the subgenus is South America with secondary centers in Australia and Africa (Whalen, 1984; D’Arcy, 1991; Symon, 1991; Nee, 1999) where endemic sections are also found. Over the past 100 years, several infrageneric classifications of Solanum have been presented (Dunal, 1852; Sendtner, 1846; Seithe, 1962; Danert, 1967; D’Arcy, 1972, 1991; Whalen, 1984; Child, 1998; Nee, 1999). Species of Solanum subg. Leptostemonum, a group originally delimited by Dunal, are characterized morphologically by prickliness, attenuate anthers and stellate pubescence. The subgenus comprises 28 sections with about 450 species (Whalen, 1984) that are encountered in many kinds of vegetation and sometimes display marked adaptation to humid or dry, hot and seasonal habitats (D’Arcy, 1991). The earliest information on the species of this group in Brazil is found in Piso and Marcgrave (1648). This work contains a description and illustration of Solanum paniculatum, collected in northeastern Brazil under the indigenous name “jurubeba.” This name is now used in Brazil for many species of Solanum used for medicinal purposes. Although Brazil is recognized as a center of diversity and endemism of the subgenus Leptostemonum (Whalen, 1984), there is no full treatment for this subgenus in the country. Understanding of this group in Brazil stems from contributions in general taxonomic works (Agra, 1999a, 2004), in local and regional floristic works (Sendtner, 1846; Smith and Downs, 1966; Carvalho, 1985; Agra, 1991, 1999a; Mentz, 2004), and most recently by the description of some new species (Huber, 1901; Agra, 1992, 1999b; Agra and Nee, 1997; Mentz and Nee, 2003a, 2003b; Nee et al., 2006). The objective of the present study is to discuss the diversity of the sections and species of Solanum subg. Leptostemonum and their geographical distributions in Brazil. 31 VI th International Solanaceae Conference Eds.: D.M. Spooner et al. Acta Hort. 745, ISHS 2007