Integrative Taxonomy Reveals Hidden Diversity in the Aloina catillum Complex (Pottiaceae, Bryophyta)

Aloina catillum is a variable moss typical of xerophytic environments in the Neotropics, characterized against other closely allied Aloina 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 A. brevirostris, A. obliquifolia, and A. rigida, we performed an integrative study including sequence data from four markers (nuclear ITS, plastid atpB-rbcL, trnG, trnL-F), morphometry, and species assembling by automatic partitioning (ASAP) algorithm. Our data suggest that A. catillum consists of at least three species: A. calceolifolia (an earlier name for A. catillum), and two species described here as a new, A. bracteata sp. nov. and A. limbata sp. nov. This latter species includes the specimens previously identified as A. obliquifolia from South America. Additionally, some morphological and molecular variability was also detected in A. limbata, but was not consistent enough to be recognized taxonomically. The study supports the presence of A. brevirostris in the Neotropics and A. rigida is tentatively excluded from South America. Full descriptions of the A. catillum s.l. species and a diagnostic key to this complex in South America are provided.