The aims of this work were to identify the species sold as "quebra-pedras" in Porto Alegre, verify signs of toxicity and establish morphological patterns that help to distinguish such species. Those species are believed to be diuretic and are used in popular medicine mainly to treat kidney and bladder affections. The samples (16) were purchased from 14 sellers who work in permanent market stalls or in public marketplaces. A bibliographic revision gathered data on the use of medicinal plants called "quebra-pedras" in several cities of Rio Grande do Sul. Signs of toxicity, chemical and biological data of these plants were reviewed from different databases and specific bibliography. Seven species were identified among those sold as "quebra-pedras" in Porto Alegre: Euphorbia prostrata and E. serpens (Euphorbiaceae), Phyllanthus niruri and P. tenellus (Phyllanthaceae), Desmodium incanum (Fabaceae), Cunila microcephala (Lamiaceae) and Heimia salicifolia (Lythraceae). The greater morphological similarity when dried and fragmented plants are sold together was verified between Phyllanthus and Euphorbia.
"Quebra-pedras"; popular medicine; morphology
