Buttercup stem. Coloured scanning electron micro- graph (SEM) of a transverse (cross) section through part of a stem of a Buttercup, Ranunculus repens, showing a vascular bundle. This is a typical dicotyledon stem. At centre is an oval vascular bundle embedded in parenchyma cells (yellow) of the cortex of the stem. Some paren- chyma cells contain chloroplasts (green). The vascular bundle contains large xylem vessels (centre right) which serve to conduct water; the nutrient conducting phloem is orange. At the outer edge of the vascular bundle is sclerenchyma tissue which supports the vascular bundle. Magnification: x113 at 5x7cm size.