Figure 1.

Leaf Blade Structures and Mechanisms of Laminar Outgrowth in Bifacial and Unifacial Leaves.

(A) Bifacial leaves in tulip (Tulipa gesneriana). Ad, adaxial; Ab, abaxial.

(B) Flattened unifacial leaves in German iris (Iris germanica).

(C) Cylindrical unifacial leaves in Welsh onion (Allium fistulosum).

(D) to (G) Schematic diagrams showing transverse sections through leaf blades and mechanisms of laminar outgrowth. Positional relationships of leaves to the SAM are indicated by circles.

(D) Bifacial leaf blade.

(E) Radialized leaf blade in abaxialized mutants.

(F) Bilaterally symmetric, flattened unifacial leaf blade.

(G) Cylindrical unifacial leaf blade.