In this study, we propose an effective method of easy and intuitive modeling of various types of multiple leaves from plants, including flowering plants and trees, and of naturally visualizing them. This method consists of two processes. The first is the procedural modeling of leaf venation patterns. The proposed method enables modeling of the growth of leaf veins based on the information of auxin detected from a binary image of a leaf blade. Therefore, a contour-based method is designed to automatically obtain information on the target auxin, required for the growth, according to blade shapes. In addition, the growth of leaf veins is procedurally modeled by dividing the veins into main, lateral, and tertiary veins. To this end, we propose a two-level growth model. The second method we introduce is a color model based on convolution sums of divisor functions to naturally simulate the color patterns of leaf surfaces. This approach automatically defines various color patterns by creating color tables for consistent changes in the convolution sums. In addition, it synthesizes three layers consisting of noise and vein glow maps. Furthermore, we perform experiments to verify whether the proposed method is effective for generating various realistic leaves.