Another useful book, though old and out of print, is this one by Martin and Child.
It sometimes appears second hand, eg. on TradeMe.
For a very useful book on New Zealand lichens, which can be downloaded free, see here:
https://bso.org.nz/lichen-guide
Lichens are quite different "plants" in that they are a combination of a fungus and an alga living together in an arrangement that benefits both - a relationship known as symbiosis.
However, between the two of them, they develop a variety of shapes, and have all kinds of structures which are found in no other plant.
Many lichens are dull grey or green-grey colours, not something to catch the eye, but others like Cladonia floerkeana shown here, are quite colourful. (The red knobs are a reproductive structure).
Some will appear a dull green -grey when dry, but when it rains they will soak up the water and become a bright green. Others can be very dark - almost invisible in the shadows in the bush.
Everyone is probably familiar with the grey lichens on the bark of trees - some are round, some are long and straggly. But other lichens on the bark of trees are visible only in that they are like patches of coloured bark, often giving some attractive patterns on tree trunks, especially kauris.
Lichens can be found in a variety of places - on rocks, trees, posts - you dont need to go to the bush to see them. Have a look in your backyard, or at the trees in the streets or parks.
