Bryophyte Succession on the Wealden Sandstone Rocks

Abstract

Rhizoid gemmae (or tubers) are described and illustrated from twenty-nine species of European mosses. A majority of the species can be recognized from the appearance of their tubers. In many species, such as those which occur in arable fields, the tubers appear to be adapted primarily as a means of surviving unfavourable conditions, while in others, such as those occurring by streams, dispersal by water may also be an important function of the gemmae. Tuber-bearing mosses are often sterile and sporopbytes are unknown in several of them.

I am grateful to Dr E. Nyholm, Mrs J. A. Paton and Dr E. F. Warburg for the loan of specimens from which to start cultures. Mr A. C. Crundwell has given me invaluable help throughout the course of this study, not only in providing information and specimens but also for the interest he has shown, and I am much indebted to him.