Article

Leaf features of Ulmus canescens, U. minor, U. glabra, and their hybrids are described in detail. Ali taxa have asymmetricalleaf bases, either due to the absence of secondary veins in one basai lobe or because of inflexion of the basai leaf margino Leaf shapes in hybrids are more or less intermediate between those of the putative parents, except for the presence of one or more distinct leaflets at the base, on the shorter side of the leaf biade, indicating a tendency of the leaf to become compound.