Studies on the growth of dicranella from a mine tip

A study was made of a moss taken from a site (Elvins Tailing Pile, Missouri) heavily polluted by heavy metals, especially Zn, Cd and Pb. The dominant form of the moss at this site was protonemal. The moss possessed some features of three different species of Dicranella (D. varia, D. rufescens and D. staphylina). This Dicranella sp. tolerated even higher levels of sine in the laboratory than the environmental levels found in the field. The highest levels led to a relatively greater decrease in the production of gemmae and leafy shoots than of protonema. The production of gemmae and leafy shoots from filamentous protonema was more sensitive to zincthan from leafy shoots. Increasing zinc levels led to an increase in the formation of intercellular spaces in the protonema; a decrease in phosphate levels also brought about the same response.