Morphometric variables of Opuntia streptacantha cladodes. 1. Cladode length (cm). 2. Cladode width (cm). 3. Maximum distance from the apical to the widest part (cm). 4. Maximum distance from the basal to the widest part (cm). 5. Number of series of areoles. 6. Areole size (mm). 7. Distances between areoles (mm). 8. Distance between lines (mm). Illustration by Rafael Ríos/CONABIO, ComenTuna et al. (2009), own modification.