Leaf morphoanatomical traits in the genus Phycella (Amaryllidaceae)

Abstract

The morphoanatomical traits of the leaves can be particularly discriminative in some taxonomic groups. The morphoanatomy of the leaves of the species of the genus Phycella Lindl. can contributeto the research process of evolutionary relationships and taxonomy in its current circumscription.Leaves from 14 Phycella populations were collected from an in vivo collection. The characterizationof the leaves was carried out in optical microphotography of samples obtained through the fresh,diaphanization and paraffin embedding methods. The leaves present a row of long epidermal cellswith anomocytic stomata, showing aerenchyma in the mesophyll, which forms large air cavities.Peripheral vascular bundles present on both sides of the leaf and large elongated bundles werefound between the cavities immersed in connective tissue. The leaves of the species can beunifacial or bifacial. Some species have one or two rows of palisade parenchyma and others haveonly rows of spongy parenchyma. The traits with most variation are the width of the lamina, thesize of the air cavities, the number of air cavities, the number of peripheral vascular bundles, the thickness of the tissues over the cavity on the adaxial face, and the thickness of the spongy parenchyma on the abaxial surface. Therefore, there are morphoanatomical traits that areinformative and contribute to the discrimination of groups of species within the genus.