Lichen is amazingly diverse. Its colours brighten up our woodlands like garish tinsel and it can form some peculiar shapes! You name it, brains, beards, corals, crusts, there'll be a lichenous look-a-like!
So, hats off to the brave person who decided to catergorise these porous puddles! Here are the three main groups...
Fruticose and filamentous
This type of lichen varies greatly. Some look like beards, some look like one-inch high shrubs (fruticose means shrubby), and filamentous lichens hang limply like matted hair. Generally, these lichens are identical in colour and form on both their upper and underside - when hanging from or erect on a branch, they can photosynthesize using both sides! If apothecia (fruiting bodies) are present on these lichens, they are likely to be stalked and disk-shaped.
Foliose
Foliose lichens can appear like layers of leaves, they are large and relatively flat - in some species, these lichens can reach several feet across! Most foliose lichens attach themselves to surfaces using plate-shaped disks on their undersides (which tend to be dark-coloured) called 'thalli'. Here in Warwickshire (and in the middle of nowhere to be exact), foliose lichens are everywhere!
Crustose
Crustose lichens live up to their name, and appear powdery, crust-like and flat. They adhere so closely to a surface that they cannot be removed without damaging it! They can be quite hard to spot, as they do not protrude or have any long fibres like frutiose, however some have stalked apothecia (fruits).
*all photos by me :)
To identify individual lichens, take a look at this! NHM lichen identifier