The reliability of direction finding, as stated in the old adage-"moss grows best on the north sides of trees"-is subject to various interpretations. A personal evaluation of the reliability of this adage was attempted in a study of the corticolous cryptogams (non-seed plants which grow on the bark of trees) at The University of Wisconsin-Milwaukee Cedar-Sauk Field Station and adjacent Cedarburg Bog. In this study the trees were inspected not only for the presence of the true mosses but also for algae, fungi, lichens and liverworts. The results summarized in this report are based on observations of over 2000 separate pieces of data which were collected from 432 "microquadrats" on 72 trees which were located along three separate transects.
Woelkerling, W.J. Some observations on corticolous cryptogams. Field Station Bulletin 4(2): 11-13.