Anatomical Characteristics of Stem and Leaf in Euphorbia hirta L

The stem and leaf anatomical studies of Euphorbia hirta L. were conducted for finding identical traits. The fresh hand sections were stained with safranin and examined under light microscope. Cross section of the stem has a circular shape where epidermis was uniseriate and isodiametric. Cortex was distinctly formed with about 5-6 rows composed of chlorenchyma and found laticifers. Tracheary elements were resembled by vessels and trachieds. In most cases, some pith cells were filled laticifers at young stage and it has a distinct gap or central cavity at maturation stage. In leaf, the epidermis was uniseriate, regular, thin walled, usually similar in diameters and covered with thin cuticle layer. Multicellular uniseriate or gland-like trichomes occur in rugose hairs at epidermis. Mesophyll was differentiated into palisade and spongy layers, was composed of parenchyma cells. The palisade layer assembled with 2 rows of cells. The spongy layer thickness was different around the midrib region, compared with other parts, has 2-6 rows of cells. Laticifers were present at the middle part of the mesophyll. Xylem elements in midrib initiated perfectly and composed of many straight rows of mainly vessels where the phloem elements were abundant and occupied a good part of the vascular bundle as a semicircle shape. The stem and leaf anatomy of this species studied here showed laticifers in cortex zone and pith cells, and middle part of the mesophyll, respectively, was a taxonomic trait for this species.