What Lichens Are Not
Isn't lichen that mossy stuff on rocks and trees? When people think of lichens, many of them think of them as a kind of moss. That could not be farther from the truth.
Although moss and lichens are both called non-vascular plants, only mosses are plants. Mosses are included in a group of non-vascular plants called bryophytes. Mosses are believed to be the ancestors of the plants we see today, like trees, flowers, and ferns. Lichens, on the other hand, are not similar in anyway to mosses or other members of the plant kingdom.
Although mosses are very primitive, they still have plant-like structures that look like and function like leaves, stems and roots. They have chloroplasts throughout their entire bodies and can photosynthesize from all sides of their structures.
Lichens, on the other hand, are completely different. They do not have any roots, stems or leaves and their chloroplasts are contained only in the algae on the top surface of the lichen.
What lichens and mosses do have in common are size and habitats. In fact, mosses retain water, which is what lichens use to prolong their growth cycle. That’s why most lichen pictures will have mosses in the photos.
So, the next time you see a bunch of "mossy" stuff hanging from a tree or sitting on a rock, ask yourself, "Is that a lichen or a moss?"