380 POPULAR FIELD BOTANY. 
are often called “Grey Moss,” but they are of the Lichen 
family; the principal is Lichen fastigiatus. There are 
several hundred species of this order found in the British 
Isles. 
Funet. Funguses. Aerial plants. No leaves or stem, but 
formed of a cap, the under side of which is either divided 
into lamellze (thin plates,) or a substance resembling sponge. 
A curious tribe of plants, of the same uses as Lichens in 
preparing the ground for larger vegetable productions. 
They are parasitic, growing principally on dead wood, 
leaves, and decaying animal matter, reducing these sub- 
stances to dust, and forming rich soils for the use of 
other plants, besides clearmg away what is useless, or might 
be injurious, if the process of decay were very slow. 
Some species are quite minute, others of large size. Of 
the former the Mould on cheese is an example; also the 
Rust in wheat, which is a fungus growing on the imside of 
the grains. The Dry-rot in wood is also a species of this 
family. It is very destructive to ships, and the timber of 
houses. The Mucor mucedo grows upon dried preserves. As- 
cophora mucedo is the mould on bread. Many are good for 
food, as Mushrooms, Truffles, Morels, and many more than 
people are generally aware of. The former are well known; 
