Identification notes
This is one of those species that is all too easy to dismiss as ‘yet another Grimmia or Schistidium’ when its greyish, hoary-looking cushions and patches are seen on sunny rocks. It’s true that it doesn’t give much away when examined in the field but with this species, patience (and good leaf sectioning skills) will reap dividends.
C. cribrosus derives its species name from its strongly cribrose peristome teeth. What this actually means is that they are sieve-like, with fine perforations. Unfortunately capsules are not very common, so another good identification character of sterile material is desirable. Examination of the leaves with a microscope will show that they look plicate above. This character is more apparent in section, when it will be seen that the plicae are bistratose and have thickened cells walls – a really distinctive character.
Molecular analysis has recently suggested that Coscinodon should be united with Grimmia but for now, it remains distinct.
Read the Field Guide account
