## 3 Results and Discussion
### Wettability Analysis  
The contact angles of Andiroba for the abaxial and adaxial sides are displayed in Figure 7. The adaxial side exhibited the smallest angle, while the abaxial side was more prominent, as shown in Table 5. This was observed for both the shortest and largest time, showing that the abaxial side is more hydrophobic. However, in general, as the contact angle was less than 90\({}^{\circ}\), the leaf has a hydrophilic behavior. Previous studies have concluded that the abaxial side of the leaves is more hydrophobic than the adaxial side, e.g., [79; 80]. Probably, the epicular wax film (usually formed by nonpolar lipid groups) is thicker on the abaxial side, promoting greater hydrophobicity. In addition, due to the plant's recurrent location, this face is more likely to receive water droplets, which justifies the evolutionary mechanism of additional protection [81]. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Parameters** & **Unit** & **S50** & **S20** & **S10** \\ \hline H & - & 0.4894 \(\pm\) 0.010 & 0.4881 \(\pm\) 0.005 & 0.4169 \(\pm\) 0.008 \\ \hline FD & - & 2.183 \(\pm\) 0.012 & 2.129 \(\pm\) 0.008 & 2.114 \(\pm\) 0.005 \\ \hline FS & - & 0.474 \(\pm\) 0.030 & 0.254 \(\pm\) 0.008 & 0.363 \(\pm\) 0.012 \\ \hline \(|\beta|\) & - & 0.029 \(\pm\) 0.002 & 0.024 \(\pm\) 0.001 & 0.056 \(\pm\) 0.009 \\ \hline E & - & 0.998 \(\pm\) 0.002 & 0.998 \(\pm\) 0.001 & 0.996 \(\pm\) 0.005 \\ \hline \(f_{out}\) & - & 0.001 \(\pm\) 0.001 & 0.001 \(\pm\) 0.001 & 0.003 \(\pm\) 0.004 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Fractal parameters of leaf surface abaxial side as a function of the scale size. The average results were expressed as mean values and standard deviation. On the abaxial side, the low roughness factor, Rf = 1.05, also explains the hydrophilic behavior of this leaf. When R\({}_{\text{f}}\) is \(\leq\)1, the leaf has a flatter surface and, therefore, more hydrophilic [82]. More hydrophobic leaves have much higher roughness factor, e.g., R\({}_{\text{f}}\) = 1.69 Thalia geniculata [81], R\({}_{\text{f}}\) = 1.55 Nelumbo nucifera [50], and R\({}_{\text{f}}\) = 1.42 Colocasia esculenta [82]. In addition, the high surface energy for this side is in accordance with the hydrophilic behavior and the low roughness factor shown. This suggests that the contact angle is also influenced by the surface terminations found on the leaf surface [83] because different topographical profiles modify the rough peak structures by changing the surface dynamics. Therefore, the unique surface architecture of the adaxial side of the leaf is designed to have greater wettability than the abaxial side, although both sides have shown hydrophilicity. In this paper, we successfully map the morphology, wettability, and fractal behavior of the topographic spatial patterns of the Amazon Andiroba leaf, using microscopy and fractal theory. The SEM images revealed differences in the morphology of the abaxial and adaxial sides of the leaf, where cells specialized in the gases exchange with the environment were only observed on the abaxial side. The internal structure of the leaf presented the cells expected for the architecture of this species. Notably, however, striated tissues were only observed on the adaxial side, which also exhibited a more hydrophilic surface than the abaxial side. The micromorphology evaluation of the abaxial side surface revealed singularities of the spatial patterns as a function of the scale size of the obtained AFM topographical images. The topographic roughness decreased when the scale decreases, and the skewness and kurtosis exhibit different patterns, mainly for the intermediate studied scale size. A similar observation of this behavior was observed by the advanced ISO parameters