Petiole anatomic aspects of four species of genero <I>Ocotea</I> Aubl. (Lauraceae) from the Rio Grande do Sul

Abstract

The petiole of the leaves of Ocotea porosa, O.diospyrifolia, O.pulchella and O.tristis presents differences, which may be of taxonomic value, when seen in transection, mainly as to the general structure and arrangement of the tissues. The vascular bundle is always col1ateral, with vascular cambium, and enveloped by a sheath of sclerenchyma. Crystals in the shape of needles and tablets, secretory cel1s with essential oils and / or mucilage and stones cells occur in the petiole of the four species mentioned above. In the O.pulchella are found lysigenous cavities.