Birthwort (Transversal Section)

This is a transversal section of the stem of a birthwort (Aristolochia sp. - Family ARISTOLOCHIACEAE) as seen under light microscope. This is a 2nd year stem.
In the center it's possible to see the vascular bundles, with xylem (red) and phloem (green). In the perifery there's a surrounding simple epidermis (with the cuticle colored red). Between the epidermis and the vascular bundles there's schlerenchyma colored red.