Fig. 3. Mechanical characterization of L. annua septum.

SEM cross-sectional images and corresponding schematics (insets) of the observed cell array relative orientation in the septum: respectively, (A) parallel, (B) normal, and (C) at an angle. (D) Macroscopic picture of a bent Lunaria septum demonstrating high flexibility. (E) Transmission diffraction grating patterns with schematic representations of the layer relative orientation observed in cross section (insets). (F) The angular resolved reflectance of the septum, with intensity normalized against a Lambertian diffuser, demonstrates the overall reflectance capacity of the septum. (G) Representative weight-normalized cumulative volume of intruded mercury as a function of the applied pressure. Kernel density plots of (H) Young modulus, (I) ultimate tensile strength, and (J) elongation of the tested septa strips. The horizontal red lines divide the Kernel plots in the 25th (bottom), 50th (intermediate), and 75th percentile (top). Photo credit: G.G., Tufts University.