The Distribution and Size of the Inter-Tracheid Pits in an Eastern Hemlock

A study of the size and distribution of bordered pits was conducted on longitudinal tracheids from a dbh section of a Tsuga canadensis L. Carr tree. Significant differences in the size of the pits were detected between springwood and summerwood tracheids, as well as between years. The linear correlation coefficient between the pit diameter and the pit torus was .88, and .83 between the pit aperture and the pit torus. Although the size of the pits increased significantly with age, the substantial increase in the number of pits per tracheid with age, was largely responsible for the increased percentage of the radial wall occupied by pits.