导管－射线间纹孔口长和宽大于3μm和2μm的树种具有侵填体，小于3μm和2μm的具有树胶。
The mean values of length and width pit aperture of vessel to parenchyma pit were greater than 3 and 2 μ m , respectively , in species having tyloses and were less than these values in species having gums .
纹孔口