Page 205 - The Forager’s Guide to Wild Foods
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Lichens Foraging, ID, and Safety
Foraging Lichens
Lichens consist of at least 2 types of organisms living
symbiotically; a structural fungus that encapsulates
Here are some guidelines for foraging edible lichens:
either a green alga or a blue-green cyanobacterium,
or both. It is now thought that a fourth organism, a 1) Lichens contain powerful acids that must always
type of yeast, may play a crucial role in the formation be leached away before you eat them. Failing to do
of some species. so can result in the worst stomachache of your life. To
The fungus protects the algae from direct sunlight and leach lichens, soak them for 3 hours in many changes
from drying out. The fungus absorbs minerals and nu- of water. If available, use 1 tsp. baking soda or potash
trients from the air and substrate, whereas the algae with each change.
and cyanobacteria produce energy via photosynthe- 2) As a general rule, stay away from yellow-hued li-
sis. Cyanobacteria also convert nitrogen gas from the chens. They may contain poisonous acids that not
air into a usable fixed form of nitrogen that can be even leaching can remove.
used to form amino acids. 3) Pay attention to the lichen’s substrate (the surface
A typical characteristic of all lichen species is the abil- it grows on). If your lichen is growing somewhere
ity to dry out during the summer and seemingly come where it’s not supposed to be, avoid it. It’s probably a
back to life in the wetter months. This ability comes different species than the one you want.
from the fact that the fungus produces microscopic 4) Lichens absorb water and nutrients through their
filaments that are rooted into the surface of the sub- bodies and many are incredibly long-lived. This
strate, so it’s only the fruiting body of the lichen that means they can accumulate a lot of pollutants, in-
you can see with the naked eye. cluding heavy metals, throughout their lives. For this
These filaments physically and chemically erode the reason, consume lichens only in small quantities and
substrate they are growing into, including rock, so from clean areas.
lichens form an important part of nutrient cycling. 5) Lichens are very slow-growing, so please harvest
Lichens dry out incredibly slowly because they can them in an ethical way. I prefer to harvest tree-growing
absorb up to 35 times their weight in water; they can lichens after a windstorm knocks them to the ground,
even absorb moisture directly from the air. leaving intact lichens to keep growing in place.
Types of Lichens Warning
Broadly speaking, there are 3 types of lichens. They Lichens are some of the most mysterious organisms
are distinguished by the type of structure the fungi on the planet. While relatively few lichens have been
produce: crustose, foliose and fruticose. These 3 main described as poisonous by scientists, it is important
types of structures, called a thallus, combine and to keep in mind that the vast majority of lichens are
morph to produce the huge variety of lichens found inedible.
all over the world. Moreover, our understanding of these organisms is
Crustose lichens are the most common and form evolving all the time.
a tight crust on the substrate that flakes off like old New species are being identified almost every year,
paint in the summer months. and many lichens can only be properly distinguished
Foliose lichens are flat, leaf-like structures that flake from each other with the help of a microscope and
off the substrate easily. chemical testing.
Fruticose lichens have an obvious bushy or shrubby With this in mind, take proper care when identifying
appearance. lichen species. Do not eat anything you cannot iden-
Lichens usually reproduce via small fragments break- tify with 100% certainty, and always seek an expert
ing off. These fragments are equipped with both the opinion first.
fungus and the algae or cyanobacteria, so it can start
growing immediately, although incredibly slowly.
Alternatively, lichens can reproduce sexually via
spores, similar to fungi.
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