Could leaf morphoanatomy characters help in the delimitation of Dyckia selloa complex?

Abstract

Among species of the genus Dyckia Schult. & Schult. f. there are 13 endemic species of the Brazilian states of Rio Grande do Sul and Santa Catarina informally treated as the Dyckia selloa complex. This study employed standard plant anatomy techniques to investigate variation in leaf morphology of species belonging to the genus Dyckia with a focus of establishing characters that help delimit the Dyckia selloa complex. The results allowed the survey of morphological and anatomical characters important for the characterization of species. Such characters include color of spines, the presence of water-storage parenchyma and mechanical hypodermis on both leaf surfaces, and the presence of tetracytic stomata on only the abaxial surface. Analyses support the current delimitation of the complex and recommend the investigation of reproductive and/or vegetative organs to better understand the relationships among these species of Dyckia .