A cladistic analysis of the genus Leucorrhinia, based on adult morphological characters, found one most parsimonous tree with a consistency index of 0.35, The evolution of large dorsal larval spines was mapped on the resulting tree. This mapping suggests that the presence of spines is the primitive state within Leucorrhinia and that they have disappeared on five different occasions, or have disappeared twice on lower branches and reappeared three times higher up in the tree.