Silicon (Si) has beneficial effects in a variety of plant species and environments. Soil and climate affect silica accumulation in given plant species. Their roles on biosilicification patterns and balance between silica and C-rich biopolymers as structural components is poorly known. Here, we studied silica deposition in situ in sugarcane leaves collected in three tropical environments differing in soil and climate. Plant silica deposits were physically extracted from leaves through wet digestion. Leaves were observed and mapped for Si by ESEM-EDX. The C-rich biopolymers in leaves were determined by the Van Soest method. Silicon accumulation in leaf was related to bioavailable Si in soil and plant transpiration. Epidermal silica deposits were either limited to silica cells or expanded to long and short cells arranged in prominent veins fully silicified, depending on whether the leaf Si concentration was lowest or highest. The size of silica deposits increased with increasing leaf Si through an increasing number of conjoined silicified cells. Ash-free cellulose and Si concentrations were negatively correlated. Soil and climate impacted markedly the magnitude of biosilicification and the counterbalance between silica and cellulose as leaf structural components.