Anatomia vegetativa e reprodutiva de Apeiba tibourbou Aubl. (Malvaceae)

Abstract

Apeiba tibourbou (Aubl.) is a native tree belonging to the Malvaceae family that is part of a project developed by IPHAN, called Boats do Brasil, as it has been widely exploited by fishermen to make rafts since colonial times. In the literature, there are ecological studies suggesting it as an alternative to reforestation because it is a pioneer species. However, works on the anatomical structure are scarce. Considering the importance of this study as a subsidy for future research, especially in the area of ecology, the present work aimed to perform the anatomical study of vegetative and reproductive structures, as well as to analyze leaf histochemical compounds. Root, stem, leaf and flower buds were collected, fixed and processed according to usual techniques in plant anatomy. The root is tetrarch, transversely reveals the well developed dermal, fundamental and vascular systems. The stem tissues are perfectly differentiated, appearing the four regions: epidermis, cortical region, vascular cylinder and medulla. Histochemistry shows the presence of alkaloids, phenolic compounds, epidermis lipids and starch grains widely distributed throughout the parenchyma. The young and mature leaves of the adult individual have similar structures, however, some differences are noticeable in the young leaf as underdeveloped sclerenchymatic tissue, absence of fibers, increased secretory channels and increased trichomes. The leaves of cultivated plants have incipient development, however, it is possible to recognize anatomical aspects in common with the adult individual. The cross-section of the flower bud reveals very differentiated sepals and petals, while the innermost whorls, androceu and gynoecium are meristematic. Therefore, it is concluded that the species A. tibourbou presents anatomical structures that are diagnostic for the Malvaceae family and are highly related to the ecophysiology of xeric environments, as it has several adaptive features against excessive water loss.