Micromorphology of the leaf surface in some species of Dryadoideae (Rosaceae)

The leaf surface of 5 species of the subfamily Dryadoideae (Rosaceae) was studied for the first time by cryoscanning electron microscopy. In the studied representatives of Dryadoideae, some signs of micromorphology were found that are characteristic of other Rosaceae. In Dryas drummondii and D. x suendermannii, cuticular folding was found on the cell surface of the adaxial leaf side. Stomatal dimorphism was found in Cercocarpus betuloides. A representative of the genus Cercocarpus had pronounced differences from the species of the genus Dryas in less pubescence of the abaxial surface with shorter and thicker trichomes, in small elongated stomata, and in smaller cells of the adaxial epidermis. Glandular trichomes and long multicellular outgrowths (possibly emergences) were found on veins in D. grandis. Structures resembling hydathodes or nectaries have also been noted on the leaf margin in this species.