Taxonomic Significance of Stem and Petiole Anatomy in Selected Rosaceae Species From Arid Region

ABSTRACT The purpose of the study was to examined the taxonomic importance of stem and petiole anatomy among some species of Rosaceae from arid localities of District Mianwali. Cross‐section of petiole and stem were made with standard microtome to observed major anatomical characters. The petiole and stems characters; epidermal cell shape, number and arrangement of the vascular bundles, presence of sclerenchyma, presence of parenchyma, presence of crystals were studied. The diagnostic characters were polygonal outline of stem in Rosa foetida , high vascular bundle numbers in Eriobotrya japonica , low layers of collenchyma in Rosa banksiae and crescent‐shaped vascular bundles in the petiole of Prunus persica , prismatic crystals in P. persica , P. armeniaca and P. amygdalus . PCA analysis with of anatomical petiole and stem features indicated that the first two principle components explained the highest percentage change with PC1 contributing the highest percentage changes. The PCA presentation showed the presence of obvious petiole and stem structural variation among the species of the Rosaceae. These anatomical characters were found to be both consistent and species‐specific and have shown to be useful taxonomically informative characters for species delimitation in the family Rosaceae.