Liverwort - Porella platyfolia (Flat leaved Scale Moss)

Bryophyta is the phylum name for the Mosses and Liverworts. They are all fairly small plants which have no internal tissue for conducting water along their stems, as the flowering plants and ferns have. Though its English name suggests that it is a moss, it is a member of the Hepaticae or Liverworts. Unlike the mosses, liverworts do not have stems with leaves with midribs, but consist of little more than a leafy frond. They do not have flowers, but very occasionally have a tiny spore capsule on a slender stalk. They do need to grow in places where there is a constant supply of water or a moist atmosphere, and often alkaline conditions. This species,Porella platyfolia (which means broad leaved), growing at Hughenden Manor, grows on a north facing flint wall along a sunken roadway so it never has direct sunlight and therefore remains damp.
Other liverworts which are farly common are Marchantia polymorpha and Pelia epiphylla which are less leaf-like, rather flattened fronds.

Porella at Hughenden Manor
Porella platyfolia close up