DIFFERENCES IN LEAF CUTICLE STRUCTURE AND EFFICACY AMONG EASTERN REDBUD AND MEXICAN REDBUD PHENOTYPES

The objective of this study was to compare the structure and efficacy in terms of retarding cuticular transpiration of leaf cuticles from ea stern redbud (Cercis canadensis L.) and dull-leaf and glossy-leaf Mexi can redbud [Cercis canadensis var, mexicana (Rose) M. Hopk.]. Leaves o f Mexican redbud exhibited several xeromorphic characteristics compare d to eastern redbud: a smaller, thicker leaf with thicker cuticles, mo re cuticular wax, a higher specific leaf mass, and greater hydrated wa ter content on a leaf area basis. Mexican redbuds with a glossy leaf d iffered from those with a dull leaf only in a thicker adaxial cuticle lacking wax crystallites on the surface. Epicuticular wax crystallites were present on the abaxial surface of all leaves examined. Detached leaves of eastern redbud had a higher water loss rate than those of Me xican redbud only on a dry mass basis, not on a leaf area basis. There was no difference in the rate of water loss by detached leaves of glo ssy-leaf and dull-leaf Mexican redbuds after 4 hours.