The torus controls the bordered pit's functions, while the margo is a porous membrane generated from the cell wall that supports the torus. Comparing the upper light dashed curve for Tracheids modelled to have angiosperm-like homogenous pit membranes with the bottom bold dashed curve for Tracheids with torus-margo membranes demonstrates the relevance of the torus-margo membrane. These Tracheids were identical to those with the native torus-margo membrane except for the pit type.