摘要：In this study, we analyzed the leaf morphology and anatomy as well as the pattern of leaf venation of six mistletoe species (Phoradendron, Viscaceae) occurring in Maringá, in the state of Paraná. The leaves are highly variable in relation to the limb and leaf apex shape. The venation type is trinervia in P. obtusissimum, P. mucronatum and P. quadrangulare, quinquenervia in P. linearifolium and P. perrottetii, and quintuplinervia in P. piperoides. The distribution of vascular bundles in all the species is acrodromous, suprabasal in P. piperoides and basal in the other species. Anatomically, the species presented similar pattern of tissue distribution: the leaves are amphystomatic with paracytic stoma, covered by a thin cuticle; the periclinal wall of the epidermis cells is thick and cutinized; the mesophyl is homogeneous with brachysclereids, dilated tracheids and idioblasts with crystals, lipidic and phenolic substances. The petiole is covered by a papilose epidermis. The vascular bundles are collateral with derived fibers of the phloem and primary xylem. The morphologic aspects are the most suitable for the distinction of Phoradendron species, together with the analyses of the venation pattern, and the anatomical aspects complement them.
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