Comparative anatomical studies of Artocarpus altilis （Parkinson） Fosberg and Artocarpus communis （J. R. ＆ G. Forster） in Nigeria

摘要

Comparative anatomy of two Artocarpus species was carried out to identify and describe anatomical characters in search of distinctive characters that could possibly be used to delimit the two taxa. Transverse, tangential and radial longitudinal sections and macerated samples of the stem and root wood were prepared onto microscopic slides. Epidermal peels and cleared leaves of the two species were made. Characteristic similarity disparity in the tissues arrangement as well as cell inclusions were noted for description and delimitation. The two Artocarpus species studied had essentially the same anatomical features; however, there were characters that seem to be taxon specific. The study revealed that at the transverse plane of the root, A. communis(J. R. & G. Forster) have predominantly solitary vessel, whereas pore multiple was predominant in A. altilis(Parkinson) Fosberg. Tyloses in vessels of the root were more frequent in A. communis than in A. altilis. In the cleared leaves, venation pattern also revealed some differences in the two species. The veins of A. communis were more or less straight and that of A. altilis were undulating especially in the secondary veins. Prismatic crystals were found in the cortex of the petiole in A. communis but not in A. altilis. Similarly, tannins were found in the root bark of A. communis but not in A. altilis. Trichomes and scales were more abundant in A. communis than in A. altilis. In the transverse section of the leaves, abaxial and adaxial epidermis were uniseriate in A. communis but only the abaxial epidermis was uniseriate in A. altilis, the adaxial epidermis was made up of 2 to 3 layers of cells. The epidermal cells in A. communis were predominantly short cylindrical shaped cells but were not so in A. altilis.