April 2020 • Nebraskaland 39
Color
Lichens come in an array of colors. Those growing in
exposed, somewhat dry habitats are often brightly-colored,
commonly red or orange. The green algae in these lichens can
be damaged by excess sunlight, and the colorful pigments,
located near the lichens' surface, protect the algae from strong
light. A lichen's color also helps regulate its temperature,
thus optimizing photosynthesis. Polar and alpine lichens,
for instance, tend to be dark-colored, which aides in the
absorption of sunlight, warming the lichens, whereas the
light color of most desert lichens refl ects sunlight, cooling
them. Lichens lacking pigments typically express the color of
their algal cells, which range from bright green to dull olive.
The crustose golden moonglow lichen (white) and gold cobblestone lichen (yellow) pattern a Sioux Quartzite (darker color
form) glacial boulder located in tallgrass prairie in Jeff erson County. Both species are commonly found on Sioux Quartzite.
