Structural analysis of subterranean organs in Zingiberaceae

Xylem structural characteristics are rarely used to separate tribes. This study aims to characterize the morphology of subterranean organs and determine both the occurrence and distribution of the vessel elements in ten species, belonging to Alpinieae and Zingibereae tribes. Species were from protected areas in the Brazilian Atlantic Rain Forest or from private cultivation areas. Roots and rhizomes processing followed both light and scanning electron microscopy procedures. According to morphological and anatomical characteristics, Euclidean distances among taxa were calculated, resulting in a dendrogram based on the unweighted pair group method with arithmetic mean (UPGMA) clustering. Despite our results indicating a similarity among all the species studied, they could be segregated by using qualitative and special metabolites characters in both the rhizome and the root. Vessel elements were found to be confined to the roots, presenting several basal characters in most of species, except for Alpinia purpurata and Etlingera species.