For the leaf sheath part, the outer side of the leaf sheath is similar to the lower side of the leaf blade that has many trichomes and protuberances. On the other hand, the inner side of the leaf sheath is smooth. Thus, there were fewer trichomes in the leaf sheath part than in the leaf blade part, but the IB of leaf sheath powder was lower than that of leaf blade powder. The reason for this discrepancy is that not only the physical condition of the surface of particles but also the chemical composition of raw materials might strongly influence self-bonding.