Morphological variation in the Vriesea procera complex (Bromeliaceae, Tillandsioideae) in the Brazilian Atlantic Rainforest, with recognition of new taxa

The family Bromeliaceae is essentially Neotropical, with high endemism and diversity in the Atlantic Rainforest Domain. Species circumscription is a major problem in the family systematics, especially in the most diverse genera. Species of the Vriesea procera complex, which occur in forests and restinga (coastal vegetation) along the South American Atlantic coast from Venezuela to southern Brazil, share the same basic vegetative and reproductive morphological patterns. However, they vary widely in the number and position of inflorescence branches as well as in the dimensions, position, and shape of the leaves and flowers in different populations. Here we aimed (i) to evaluate the morphological variation in the V. procera complex, through morphometric analyses of natural populations along the Brazilian Atlantic Rainforest; and (ii) to determine the taxonomic relationships among these species, establishing the validity and the limits of variation of the taxa through taxonomic treatment. Fourteen natural populations, 271 individuals and 36 morphometric variables were analyzed. Kruskal-Wallis tests and discriminant analyses were conducted to test statistical differences between previously established groups. Of an original three species and three varieties, our data allowed us to recognize six species, including three new taxa and one new name and status. The resulting taxa are distinguished by the inflorescence and leaf sizes and especially by floral characteristics such as the length of bracts, sepals, petals, stamens, and pistils, besides the petal apex posture and relative position of the stamen during anthesis. Recognition of cryptic species under the names V. procera and V. neoglutinosa is an important step toward a better understanding of the biodiversity of the Brazilian Atlantic Rainforest.