A sunny summer day in the dunes, when the ground is very hot and dry, is not the ideal weather for mosses. However, they have developed a number of adaptations to protect themselves from dehydration. They can go into a kind of summer hibernation. The living functions work at a low level, so that little water is needed to survive. The moss appears withered and dried up. But after a rain shower, it absorbs the water and turns green.

Some moss species, especially those in open areas, have a glassy hair on the tip of the leaf. It is actually an elongation of the leaf vein but lacks the green color. This 'hair' protects the plant from dehydration by reflecting sunlight. During dry spells, the glassy hair of some moss species will stand at a right angle to the leaf tip in order to protect the plant even better. These hairs give the moss a grayish film, which is easy to see in the above photo of heath star moss.

Moss names, if they exist, generally refer to a feature of the spore capsule. True mosses are leafy. For the inexperienced eye, all liverworts and hornworts (and even lichens) are referred to as moss, though technically they are two different members of the bryophyte family. Leafy mosses always have leaves wrapped around the stem. They can be divided into three groups: bog-moss, screw-moss and feather-moss.

Bog-mosses grow in poor acidic environments, which they help to acidify even more. Because bog-mosses strongly resemble each other, they can only be identified under the microscope. Bog-mosses are common in peat-bogs, trenches and in wet areas in acidic forests. They can also grow in dune slacks.

Screw-mosses grow erect and rarely branch off. The leaves have obvious veins and the spore capsules grow out of the top of the branches. The Dutch name, 'top capsule moss', refers to this feature. The English name comes from the fact that the teeth surrounding the 'mouth' of the spore capsule are often twisted in a spiral. Screw-mosses grow on walls, soil, rocks, trees and in sand dunes.

Feather-moss has a feather-like shape, although it is sometimes irregularly branched. It can grow erect, but often grows flattened on the ground. In Dutch, these species of moss are literally called 'sleeping moss'. You know whether it is a feather-moss when the spore capsules evolve along the stems as opposed to the screw-mosses which grow out of the top.