Jerry Jenkins, White Creek, N.Y.
Moss Lesson 4 is a long lesson about 36 mosses that occur on ordinary nonlimy boulders in deciduous or mixed woods. It argues that deciduous woods are poor bryophyte habitats because of problems with litter and dryness. Boulders are good spots in a bad habitat, and have a large species pool and often moderate moss cover. This makes understanding boulder ecology and boulder mosses central to the study of forest mosses: if you understand boulders and the boulder mosses, you will a lot about forests and forest mosses as a whole.