Anatomical variations in the aerial roots of Oenocarpus bataua (Arecaceae)

Abstract

The anatomy of aerial short roots of Oenocarpus bataua that arise from the stem base up to approximately 80 cm from above ground level is described, comparing this structure between individuals at different distances from the apex and between primary and secondary roots. Samples were collected in Zamora Chinchipe (Ecuador). Transverse, longitudinal sections and macerates were made using classic techniques. The studied roots lacked apical meristematic tissue. Principal variations between individuals are the presence of medullar isolated tracheary elements and deep lobulated endodermis in thicker primary roots. Another differences between individuals are found in the exodermis and outer cortex in terms of absence, presence or variation on the number of cell layers and wall thickening, while the structure of the inner cortex showed more constancy. At different levels from the apex, primary roots show centrifugal sclerification of the fundamental tissue bordering the vascular tissue. Secondary roots have a simpler and less variable anatomy.

Key words:
Arecoideae; vegetative structure; histology; palm