Fig. 3. Morphology and anatomy of wild-type and ral1 leaf blade commissural veins. (A,M,N) Wild type. (B-L,O,P) ral1. (A-L) Dark-field images of cleared leaves. (A) Uninterrupted commissural vein connecting two longitudinal veins. (B,C) Interrupted simple (B) or compound (C) commissural vein associated with one longitudinal vein. (D,E) Interrupted simple (D) or compound (E) commissural vein associated with two longitudinal veins. (F) Uninterrupted `Y' vein forming two connections with one longitudinal vein and one with the other. (G-K) Y veins showing interruptions at different positions. (L) Isolated patch of xylem elements (vascular island). (M-P) Paradermal sections through mature leaf blades. (M) Uninterrupted commissural vein connecting two longitudinal veins. (N) Detail of M. (O) Interrupted simple commissural vein associated with two longitudinal veins. (P) Detail of O. Scale bars: (A-L) 50 µm (M-P) 25 µm.