Author : Yupa Worayos

Summary : Study of the elements of nearly all known species (21 out of 23) of the genus Oryza (Gramineae) revealed that characters of the perforation plate in roots, stems and leaves, were of considerable value in classifying the species and understanding their relationships. The predominant type of lateral wall pattern of secondary thickening was the reticulate, all others being irregularly and rarely found. The second-order thickenings were represented by oblique strands, strands ontogenetically modified into sheets, or rarely sheets. Almost all pitted elements had oval to circular bordered pits. The variations in lateral wall pattern of secondary wall thickening was discussed; there have little value indicating phylogeny.