Numerous Wood Tissues on Mars

[link to www.flickr.com (secure)]
In the above figure, red arrows point to pits on the remains of wood cells (tracheids) on Mars (see notes 1, 2).
So, the figure shows numerous wood tissues. The wood tissues are remnants of wooden products made by Martians.

Note 1: Introduction to wood cells on Mars: [link to www.flickr.com (secure)]
Note 2: Numerous wooden products on Mars: [link to www.flickr.com (secure)]