This is another one of the names for Leucobryum albidum, as mentioned on Monday. The story goes that this moss can grow in patches that are large enough to use as a seat on the forest floor. When you touch the top of this moss cushion it feels soft and dry. However you should only offer this seat to your mother-in-law. (Two assumptions of this tale are that you have a mother-in-law and that you like playing tricks on her.) When she sits down on this moss she will experience one of the benefits of growing in a cushion shaped colony. All of the individuals packed together function as a sponge and store water within the colony, so that there is moisture available for the moss to undergo photosynthesis even when it is dry. Having sat on this cushion your mother-in-law will end up with a very wet rear. Thus Leucobryum albidum also has been called the mother-in-law's cushion.
12 minutes ago in The Phytophactor