Integrative Taxonomy Reveals Hidden Diversity in the <i>Aloina catillum</i> Complex (Pottiaceae, Bryophyta)

<i>Aloina catillum</i> is a variable moss typical of xerophytic environments in the Neotropics, characterized against other closely allied <i>Aloina</i> species with well-differentiated leaf border by its setae twisted to the left throughout. In order to clarify its variability and its relationships with the allied species with differentiated leaf border <i>A. brevirostris</i>, <i>A. obliquifolia</i>, and <i>A. rigida</i>, we performed an integrative study including sequence data from four markers (nuclear ITS, plastid <i>atp</i>B-<i>rbc</i>L, <i>trn</i>G, <i>trn</i>L-F), morphometry, and species assembling by automatic partitioning (ASAP) algorithm. Our data suggest that <i>A. catillum</i> consists of at least three species: <i>A. calceolifolia</i> (an earlier name for <i>A</i>. <i>catillum</i>), and two species described here as a new, <i>A. bracteata</i> sp. nov. and <i>A. limbata</i> sp. nov. This latter species includes the specimens previously identified as <i>A. obliquifolia</i> from South America. Additionally, some morphological and molecular variability was also detected in <i>A. limbata</i>, but was not consistent enough to be recognized taxonomically. The study supports the presence of <i>A. brevirostris</i> in the Neotropics and <i>A. rigida</i> is tentatively excluded from South America. Full descriptions of the <i>A. catillum</i> s.l. species and a diagnostic key to this complex in South America are provided.