Fig. 2. S. kraussiana leaves comprise three chloroplast-containing cell layers. (A) Transverse section through leaves arranged around an apex showing the three main cell layers of the leaf, and the downwards orientation of chloroplasts in the mesophyll. The asterisk indicates the position of the meristem; red arrowheads indicate the abaxial surfaces of the dorsal (d) and ventral (v) leaves; black arrows indicate large chloroplasts in the mesophyll; the blue arrow indicates a guard cell. Scale bar: 40 µm. (B) Scan through all three layers of the leaf showing a white au/- sector in the upper two layers of the leaf. The abaxial epidermis is au/+. Scale bar: 10 µm.