Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Ant pollination is a debated topic that requires more attention in order to clarify the role of ants as potential pollinators. Although many authors consider ants as mere nectar robbers, there are studies proving that ants may act as pollinators and that some plants even have flower traits acting as ant attractors. In this study, we evaluated the role of the ants in pollination of Blutaparon portulacoides inflorescences. This plant species has most of the traits favorable for ant pollination, such as short and aggregated inflorescences, and synchronized blooming as well as growing in an environment where ant pollination is likely to occur. Our results show that ants are the most abundant visitors throughout the day and that there is no effect of ant integument on pollen germination. Furthermore, the flower visitor exclusion experiment showed that ants have a role in the pollination of B. portulacoides by promoting seed formation. Ants can have an important part in the pollination of B. portulacoides in a scenario where winged insects are absent or scarce.103221227Coordenacao de Aperfeiconamento de Pessoal de Ensino Superior (CAPES)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [2014/12486-8, 2012/23399-3]Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)