Morphology and development of leaf papillae in the Pilotrichaceae

Abstract

Sporophyte morphology has been traditionally used in taxonomic studies of pleurocarpous mosses. However, the gametophyte morphology of the Pilotrichaceae still holds interesting and under-investigated characters. Here, we conducted an in-depth investigation of the morphology and development of Pilotrichaceae leaf papillae and assessed their usefulness in inferring the evolutionary history of the family. Specimens were observed under scanning electron microscopy, and we identified seven morphological types of papillae, as well as two different pathways of development. Our results suggest that papilla morphology and development are phylogenetically informative in the Pilotrichaceae.