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The morphological features of the cuticles of the leaves, nectaries and stamen filaments of eleven newly published species of Eucalyptus from Central Australia are described and illustrated. The species form four groupS. Within each group, the gross morphology of the species is sufficiently uniform to present difficulty in identification of specimenS. However, the species differ from each other in both qualitative and quantitative cuticular features. The quantitative features include stomatal size and the frequency spectra of subsidiary cells. The abaxial and adaxial frequency spectra of a given species are usually different from each other, but the spectra of different specimens of the same species are closely similar and differ from those of other species of the same group. The general features of the nectary are described. The species differ in nectary pore size, whether the pores are complanate or sunk, etc. Other microscopic features of the nectary cuticles are also species-specific. Different species are shown to have different patterns of the cuticular ornamentation of the stamen filaments. The importance of cuticular features in identification and definitions of the term ‘subsidiary cell’ are discussed. Cuticular ornamentation differs in leaves, nectaries and stamen filaments, yet the nature of the cuticle remains the same. Species with relatively large stomata may have small nectary pores, and vice versa. The genetic control of the cuticular features is different in and independent for each tissue, in the leaf even for the abaxial and adaxial surfaces. The adaptive value of cuticular features, especially of the leaves, and the radiative evolution of the Central Australian bloodwoods are discussed. |
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