Cross section in a petiole of Ficus
The paraffin section has been stained with astra blue and basic fuchsin. The petiole is circular. Below the uniseriate epidermis (blue arrow on the left) there are layers of collenchyma (co, red arrows) then the ground tissue, parenchyma. The vascular bundles are arranged on a ring with xylem (in red) towards the center and phloem (in bleu) towards the periphery. The center of the petiole is occupied by ground tissue e.g. parenchyma.
Detail of the ground tissue, parenchyma with small intercellular spaces (blue arrow) and angular collenchyma with thick cellulosic walls (filled intercellular spaces).