Microscopic diagnosis of the leaf and stem of Piper solmsianum C.DC

Abstract

Piper solmsianum C.DC., which is popularly known as pariparoba, is a shrub that measures 1-3 m in height and it inhabits areas with wet tropical soils. The objective of this study was to analyze the leaf and stem anatomy using light microscopy, scanning electron micrographs, and energy-dispersive X-ray spectroscopy in order to provide information for species identification. The anatomical profile showed the following main microscopic markers: hypostomatic leaf; hypodermis layer on both sides; pearl glands; biconvex midrib shape; five collateral vascular bundles in open arc with the central bundle larger than the others; circular stem shape; collateral vascular bundles arranged in two rings; sinuous sclerenchymatic sheath in the pith; secretory idioblasts; and starch grains in the mesophyll, in the ground parenchyma of the midrib, petiole, and in the stem; and six morphotypes of calcium oxalate crystals (styloids, cuneiform, tabular crystal rosettes, cuneiform crystal rosettes, elongated square dipyramids, as well as very elongated square dipyramids).

Morphoanatomical profile of five species of Piper L. from Bangladesh and its taxonomic significance

“…Nakamura et al (2015) opines that the origin of the sub-epidermal layers or hypodermis in Piper leaves is the ground meristem. The number of hypodermal layers is considered by many authors as a taxonomic character to identify Piper species (Raman et al, 2012;Machado et al, 2015;Santos et al, 2015;Bertocco et al, 2017). The present investigation also confirms variable numbers of hypodermis on both surfaces across the species (Table 2).…”

“…3G-I). Such idioblasts have additional secretory functions and reported from many other species of Piper (Raman et al, 2012;Machado et al, 2015;Nakamura et al, 2015;Santos et al, 2015;Bertocco et al, 2017).…”

“…Though oil droplets are present occasionally in different tissues of the stem of other studied species, no oleoresins are present in other species. However, occurrence of such compounds are reported to be common in other species of Piper by many workers (Silva et al, 2014;Machado et al, 2015;Santos et al, 2015;Bertocco et al, 2017).…”

“…P. longum can easily be differentiated from remaining species by its diacytic stomata (Table 2). Tetracytic stomata are common in Piper species (Santos et al, 2015;Bertocco et al, 2017). However, due to the presence of multiple types of stomata in case of inter-and intra-species this feature may not be helpful in the delimitation of species (Santos et al, 2018).…”

“…In this context, anatomical studies have significant role to provide additional data for solving taxonomic problems. Despite the varied importance of this genus, little anatomical studies have been done on different species of Piper across the world (Ravindran and Rameshree, 1998;Lakshmi and Naidu, 2010;Raman et al, 2012;Machado et al, 2015;Trueba et al, 2015;Bertocco et al, 2017;Silva et al, 2017). Most of the anatomical studies are concentrated on economically important and widely known species, e.g.…”