Apomictic plants are less dependent on pollinator services and able to occupy more diverse habitats than sexual species. However, such assumptions are based on temperate species, and comparable evaluation for species-rich Neotropical taxa is lacking. In this context, the Melastomataceae is a predominantly Neotropical angiosperm family with many apomictic species, which is common in the Campos Rupestres, endemism-rich vegetation on rocky outcrops in central Brazil. In this study, the breeding system of some Campo Rupestre Melastomataceae was evaluated, and breeding system studies for New World species were surveyed to test the hypothesis that apomixis is associated with wide distributions, whilst sexual species have more restricted areas. The breeding systems of 20 Campo Rupestre Melastomataceae were studied using hand pollinations and pollen-tube growth analysis. In addition, breeding system information was compiled for 124 New World species of Melastomataceae with either wide (>1000 km) or restricted distributions. Most (80 %) of the Campo Rupestre species studied were self-compatible. Self-incompatibility in Microlicia viminalis was associated with pollen-tube arrest in the style, as described for other Melastomataceae, but most self-incompatible species analysed showed pollen-tube growth to the ovary irrespective of pollination treatment. Apomictic species showed lower pollen viability and were less frequent among the Campo Rupestre plants. Among the New World species compiled, 43 were apomictic and 77 sexual (24 self-incompatible and 53 self-compatible). Most apomictic (86 %) and self-incompatible species (71 %) presented wide distributions, whilst restricted distributions predominate only among the self-compatible ones (53 %). Self-compatibility and dependence on biotic pollination were characteristic of Campo Rupestre and narrowly distributed New World Melastomataceae species, whilst apomictics are widely distributed. This is, to a certain extent, similar to the geographical parthenogenesis pattern of temperate apomictics.

Poteranthera (Melastomataceae) is a genus of small, annual herbs with narrow leaves, that inhabit humid savannas in South America and are visible only when in bloom. Due to their size and paucity of collections, the phylogenetic position of Poteranthera has been uncertain to this point. Poteranthera has been at times associated, confused, or placed in Acisanthera and/or Siphanthera. Phylogenetic analyses based on DNA sequence data place Poteranthera unequivocally within the Microlicieae and not closely related to Acisanthera or Siphantera. These results are consistent with seed and anther morphology. Putative morphological synapomorphies for this genus are the glandular hairs restricted to the leaf margins and the apically constricted hypanthium. Based on morphology, Acisanthera leptalea seems better placed in Poteranthera and the new combination Poteranthera leptalea is made. An expanded generic description is also provided.

In heterantherous flowers, some anthers have an attraction and feeding function, while others are related to plant reproduction. Microlicia cordata has dimorphic stamens organized in two cycles: the antesepalous one with large stamens and pink anthers, and the antepetalous one with small stamens and yellow anthers. Division of labor was analyzed using the parameters of structure, composition, amount and estimated viability of pollen, and the color of floral parts. The anthers of the pollinating stamens were larger than the anthers of the feeding stamens, although anatomically similar. There was a difference in the amount of pollen produced by the anthers of the two cycles, but no difference was found in pollen viability. Considering a bee color vision model, the color of the anthers of the pollinating stamens contrasted less with that of the corolla, and thus is probably less attractive to visitors. Conversely, the anthers of the feeding stamens and the ventral appendage of the connective of the pollinating stamens contrasted more with the corolla, presenting the same color to the pollinators. These results are in accordance with the idea of division of labor among anthers of heterantherous flowers, especially regarding the quantity of pollen and the color of the floral parts.

O presente estudo fornece o tratamento taxonômico das espécies de Microlicieae para o município de Mucugê, Chapada Diamantina, Bahia, Brasil. Foram catalogadas 27 espécies distribuídas nos gêneros Microlicia (24 espécies), Lavoisiera (L. harleyi e L. nervulosa) e Trembleya (T. parviflora). Com exceção de M. fasciculata, M. viminalis e T. parviflora, as demais espécies encontradas em Mucugê são endêmicas da Chapada Diamantina. Entre as espécies de Microlicia, quatro foram recentemente descritas e outras quatro ainda necessitam de estudos complementares para sua identificação. Anteras poliesporangiadas foram descritas pela primeira vez para 11 espécies de Microlicia. As espécies de Microlicieae ocupam áreas de campo rupestre em altitudes entre 900-1.500 m, em solos arenosos ou pedregosos, às vezes associadas a cursos d'água.