|
|
|
|
|
Lichens are
an important, if overlooked, part of the plant kingdom. Over 15,000
species have been identified worldwide, and they grow in all parts
of the earth, from the tropical jungles to the extremely hostile
environments of Antarctica, the alpine tundra, and bare lava flows.
They are attached to a variety of substrates, including the soil,
bark, mosses, and rocks old gravestones are a common site and
cliffs and desert landscapes can be drenched in the chartreuse,
yellow, green, or orange of various lichen species. A few blow
about unattached to anything. |
|
|
|
|
|
|
|
|
Throughout
history, lichens have served as sources of dyes, for medicinal
purposes, and as forage. They are a staple of the caribou diet.
Because of some lichens' extremely slow growth rate (some living
thalli are up to 10,000 years old), scientists are using them to
date glacial recessions. Many lichens are sensitive to air
pollution and are being used to determine regional air
quality. |
|
|
|
|
|
|
|
|
Lichens are
a conspicuous part of the scenery of the Rocky Mountains,
particularly those occurring on rocks. It is natural that outdoor
people see them and want to know about them as organisms, and to
find out what their names are. This book presupposes no prior
knowledge of lichens, and aims at recognition of the most commonly
encountered kinds, using only the eyes and the help of a hand lens,
which can be acquired at most camera stores. Serious study of
lichens can be very time-consuming and frustrating, requiring the
help of an expert, access to an excellent collection (herbarium) of
specimens, and extensive literature in many languages. But there is
no reason for laymen to bother themselves with studies in depth;
many lichen species are very easy to recognize and not very
variable; anyone can master the recognition of those dealt with in
this book. |
|
|
|
|
|
|
|
|
A lichen is
an intimate association of a fungus and an alga. The fungus is the
part that we see, while the algae are hidden just under
the |
|
|
|
|
