Morphological and anatomical features associated with epiphytism among the pleurocarpous mosses — one basis for further research on adaptations and their evolution

Abstract

Based on morphological information from 619 pleurocarpous mosses occurring in 14 habitats, character states that potentially represent especially epiphytic adaptations are explored, by statistically evaluating differences in frequencies of states among species occurring in different habitats or habitat groups. Character states that are most frequent among epiphytes and could potentially have evolved as adaptations to epiphytism include: absence of a stem central strand, lack of perigonial and vaginular paraphyses, short seta, cylindrical and straight orthotropous spore capsules, short exothecial cells, strongly reduced exostomes with papillose or smooth lower outsides, entire margins, and lacking border, low endostome basal membrane and short or rudimentary cilia, and large spores. The presented data on the distribution of character states among habitats should serve as a basis for exploring both whether certain features are true adaptations and what is the function of different morphological structures among the pleurocarpous mosses.

Keywords:

• Adaptation
• Character state
• Gametophyte
• Habitat
• Sporophyte

I thank Irene Bisang for valuable discussions regarding habitat adaptations. I appreciate constructive referee comments on the manuscript.

Taxonomic Additions and Changes: Nil.