Comparative anatomy of the secondary xylem in the "?Gruinales?" and "?Terebinthales"?, of Wettstein. With reference to taxonomic grouping

Abstract

In the Wettstein system, the composition of the Gruinales and Terebinthales orders differs from Engler, Hallier and Hutchinson systems. The taxonomic principles supported in this research are based on the observation of microscopic preparations of more than 1000 species, of 440 genera belonging to 37 families.