TL;DR: Only the three New Caledonian species of Section Notosmanthus lacked tori, which serves to isolate this section from the remainder of the genus Osmanthus.
Abstract: Torus thickenings of pit membranes are found not only in gymnosperms, but also in certain genera of dicotyledons. One such genus is Osmanthus. Wood from 17 species of Osmanthus was searched for tori. Fourteen species from three of the four sections investigated possessed these thickenings. Ten of the species represent new records. Only the three New Caledonian species of Section Notosmanthus lacked tori. This observation in combination with other factors serves to isolate this section from the remainder of the genus.