*2.2. Computerized Tomography*

The computerized tomography (CT) was performed using a two-slide Siemens Emotion Duo 1 scanner with a standard protocol for lung tissue diagnosis (113 mA and 130 kV). The tomograms were acquired in slices of 3 mm with a separation between every measure of 0.5 mm and processed in the transverse, sagittal, and coronal planes.

#### *2.3. Sample Preparation*

Table 1 summarizes the samples analyzed and the analyses performed. The sampling areas are reported in Figure S2. Cross-section samples were imbibed in Nic Tone® transparent acrylic resin and polished until the sample surface was exposed. One of the cross-sections from the polychromy was imbibed initially with KBr and then in Implex® polyester resin. It was polished until the sample surface was exposed [34].

The fibers from the paper samples were partially separated under the stereomicroscope and then introduced into a test tube with distilled water and completely separated. A drop of the fibers sample was put over a glass slide and covered for observation.

The maize stem sample was boiled and cut using a razor blade to obtain a transverse view of the cellular structures. The slides were added to a sample holder with carbon adhesive tape.

**Table 1.** List of samples analyzed and a summary of the analysis performed.


#### *2.4. Stereo and Optical Microscopy*

The samples were observed and documented with a stereomicroscope Leica model EZ4HD and an optical microscope Leica model DM 4000 M with a Leica digital camera model DFC 450 C using 20× and 50× magnifications. We processed the images with the Leica Application Suite 4.0 software.
