Figure 7.23. Tissue failure occurs via four mechanisms: cleavage (A), illustrated by a sweetpotato root; slip (B), where the impact force causes the neighboring cells of the potato tuber to break apart at a 45E angle; bruising (C), illustrated by petal bruising (clockwise from top left: Impatiens wallerance Hook. f.; Gardenia zasminoceides Ellis; Mandelvillia laxa Woodson; Hedychium coronarium Hoenig.); and buckling (D), illustrated by the mechanical failure of an African violet petiole.