Palynotaxonomy of endemic species of Anteremanthus H. Rob., Hololepis DC., Maschalostachys Loeuille and Roque, and Proteopsis Mart. and Zucc. ex Sch.Bip. (Asteraceae: Vernonieae: Lychnophorinae) from Brazil

Endemic genera of the subtribe Lychnophorinae (Asteraceae: Vernonieae) remain insufficiently characterized from a palynological perspective, despite their taxonomic relevance and restricted distribution in the Brazilian campo rupestre. In this study, pollen morphology of Anteremanthus, Hololepis, Maschalostachys, and Proteopsis species was investigated using light and scanning electron microscopy to evaluate the taxonomic significance of pollen characters at generic and specific levels. Quantitative pollen grain data were examined by descriptive, Analysis of Variance (ANOVA) and Principal Component Analysis (PCA) analysis. The pollen grains are medium-sized, isopolar, prolate-spheroidal and oblate-spheroidal, tricolporate, with lalongate, lolongate or nearly circular endoaperture, and a subechinolophate, microperforate sexine. Quantitative and qualitative variation was observed in pollen size, aperture morphology, exine thickness, and echinae dimensions. A palynological identification key based on these characters is provided. The presence of Y-shaped muri in the apocolpium emerged as a potentially diagnostic feature for Proteopsis, while other pollen traits were useful for distinguishing species within Maschalostachys. The quantitative data, statistically analyzed, demonstrated taxonomic value for distinguishing among species. These findings reinforce the value of pollen morphology as complementary taxonomic evidence for Lychnophorinae and contribute new comparative data for endemic members of Vernonieae.