Fig. 6. Disruptions of the blade-sheath boundary in sem1 mutant leaves. Scanning electron micrograph images of the epidermal surfaces of non-mutant (A), and mutant (B) leaf primordia soon after initiation of the ligule (arrows), separating the blade (b) from the sheath (s). The mutant ligule (B) is displaced distally in the midrib region. (C) Non-mutant young adult leaf at maturity. lg, ligule. (D) The non-mutant midrib and blade (b) distal to the ligule depicted in C. (E-I) Images of a sem1 mutant, young adult leaf showing ligule displacement over the midrib (E), an ectopic second ligule (F), the region distal to the ectopic second ligule (G), an ectopic third ligule (H), and (I) normal cell types located distal to the disturbed region. Scale bar: 300 µm.