Pinoxylon Dakotense Knowlton from the Cretaceous of the Black Hills

Abstract

The wood is characterized by (1) normally developed vertical resin ducts; (2) rays of abietinean type; (3) tracheids bearing bordered pits arranged on the radial walls, partly as in modern Abietineae and partly as in existing Arau-carineae; and (4) terminal, and to some extent, diffuse wood parenchyma. The affinities of Pinoxylon seem to be strongly Abietinean but the evidence is not conclusive.