Fig. 4. Effects of phan and hb mutations on leaf dorsoventrality. (A) Shoots of wild type, the phan single mutant and a phan hb double mutant. (B) Transverse sections through the leaf midrib (lf) and petiole (pet) of wild type showing asymmetry along the dorsoventral axis (top to bottom of page). Needle-like leaves of phan single and phan hb double mutants (right) both lack dorsoventral asymmetry.