A, B Ipomoea maranhensis A arrangement of vascular bundles in U; prominent/concave main rib shape B dorsiventral mesophyll C–F I. burchellii C arrangement of vascular bundles in V; convex/flat main rib shape D mesophyll isobilateral E glandular trichomes restricted to the abaxial surface of the leaf (red arrow) F parenchymatous tissue with isodiametric cells (Photos by E. Pereira Arruda). AD: adaxial epidermis; AB: abaxial epidermis; Is: isodiametric cells; Pa: Parenchymatous tissue; Pp: palisade parenchyma; Sp: spongy parenchyma; Vb: vascular bundle; Tr: trichome.