Morphoanatomy of Schultesia pachyphylla (Gentianaceae): a discordant pattern in the genus

Abstract

Schultesia Mart. comprises 21 closely related taxa. The revision of the genus showed that Schultesia pachyphylla Griseb. and Xestaea lisianthoides Griseb. are different from other species. The aim of this study was to describe the morphoanatomy of S. pachyphylla, comparing it with other Schultesia species and X. lisianthoides, and to provide data on their geographical distribution and habitat. Morphological and anatomical data were subjected to multivariate analysis. Schultesia pachyphylla is endemic to the state of Bahia, Brazil, and is separated from the other species by having 5-merous flowers, 5-winged calyx, wings between the calyx lobes, loss of interveinal tissue on sepals during fruit maturation, dark red colored immature calyces, capsules opening from base to apex, 3-anaporate pollen grains, and epidermal papillae evident in the field. Schultesia pachyphylla has amphistomatic leaves with anisocytic stomata, uniseriate epidermis, dorsiventral mesophyll, and bicollateral vascular bundles. The stem has small wings, cortical and medullary parenchyma, and internal phloem. Foliar colleters and nectaries on leaves and stem were observed. We believe that morphological and anatomical data could support the creation of a monotypic genus or the relocation of this species into another genus. Phylogenetic analyses are in progress to define the species’ positioning.