The nectaropolliniferous flora used byTrigona (Tetragonisca) angustula(Apidae, Meliponinae), was studied by melissopalinological analysis at Chiapas, southern Mexico, in two zones with different altitudes and vegetation (Santa Teresita and Unión Juárez). In both areas monthly samples of honey, pollen, and larval feed were taking for a full year, from a nest established expressly for the purpose. A total of 105 plant species were identified at Santa Teresita, of which only 28 taxa were present in percentages higher than 10; of these, seven taxa are nectariferous, ten nectaropolliniferous and eleven polliniferous sources, of which four taxa are found exclusively in larval food. The values of niche size (H') at Santa Teresita indicated less diversity and availability of sources, in comparison with Unión Juárez, where the evenness values (J') have a tendency toward heterogeneity. At Unión Juárez, a total of 127 plant species were registered of which only 30 taxa were present in frequencies higher than 10%; of these ten species are nectariferous, five taxa are nectaropolliniferous, and 15 species are polliniferous, and of the last category three taxa are found exclusively in brood cells. At Unión Juárez the values of niche size (H') for the three sources are higher than at Santa Teresita, and the evenness (J') values are homogeneous, and showed tendency toward evenness, indicating more diversity and availability in this area.