Lichen Identification

How to Identify Lichens by Photo

Want to know how to identify lichen from a photo? With Botan, you can do this in a few simple steps:

1. Taking a photo. Take a new picture or select one from your device’s gallery.
2. Analysis. Botan examines the shape, color, and surface texture in the image.
3. Matching. Your image is compared against the species in our database.
4. Result. You receive a suggested species ID along with detailed information about it.
5. Try again if necessary. If the result seems inaccurate, try uploading a different photo.

Clear and close-up shots that show the shape and surface texture work best for an accurate identification. It is also helpful to include a wider shot that shows the section of bark or rock where the organism is growing. Treat the result as a suggestion and be sure to compare it against the actual specimen.

Types of Lichens

You can classify them by their growth form. This is the first thing to keep in mind in lichen identification. There are three main types: crustose, foliose, and fruticose. The appearance of each type varies depending on the substrate — whether it is bark, rock, or soil.

Crustose Lichens

Crustose types form a dense crust-like layer. They are firmly attached to their substrate, and in most cases, you cannot remove them without damaging the surface upon which they grow. They can be found on rocks, tree bark, and old walls. Their coloration ranges from gray and white to bright orange.

Foliose Lichens

Specimens that consist of flat, leaf-like lobes are classified as foliose. Unlike crustose ones, you can usually lift the edges from the surface. The underside is often lighter in color than the top. Look for them on branches, trunks, and rocks.

Fruticose Lichens

In appearance, fruticose types resemble small shrubs, threads, or strands. They grow vertically upward or hang downward. Unlike the other two types, they do not lie flat against the surface but instead extend away from it.

What to Look for When Identifying Lichens

Any reliable lichen identification guide is based on observable external features. Color, texture, shape, and habitat provide important clues. Together, these characteristics help narrow down the range of possible species.

Color and Surface Texture

Lichens can be gray, green, yellow, orange, white, or black. Their coloration may change depending on moisture levels: they often appear greener when wet and paler when dry.

Since color alone is not enough to accurately identify a species, be sure to examine the surface. Look for powdery patches, tiny cup-like structures, raised dots, or cracks. If possible, use a hand lens. 

Shape and Growth Form

Growth form is the simplest way to begin classification. Crustose types adhere tightly to their substrate. Foliose species have lobes with free edges. Fruticose ones form tufts or strands, or resemble tiny shrubs. 

Observe the form: does it lie flat against the surface, create folds, or grow vertically upward? Every detail helps to rule out incorrect options.

Where It Grows

The surface on which a lichen grows provides additional clues. Some species are located on tree bark, rocks, soil, or weathered wood. For tree lichen identification, note the bark texture, the host tree, and the level of light exposure. 

However, the surface alone is not enough to definitively identify a species. Always verify any identification hypothesis based on the growth substrate by examining the form and texture.

Lichens vs. Mosses: Key Differences

Lichens and mosses often share the same bark and stones. However, they are not related. The first one forms through a symbiosis between a fungus and a photosynthetic partner. 

In this relationship, the fungus is the mycobiont, while the partner is the photobiont — typically a green alga or a cyanobacterium. Mosses, on the other hand, are true plants. Below are the major differences between them.

Common Lichen Identification Mistakes

Lichen species identification requires patience, as even small errors can lead to an incorrect result. The three most common mistakes are:

1. Relying solely on color. Moisture, light, and age all change its appearance. Before drawing a conclusion, consider the color in relation to the shape and surface texture.
2. Confusing it with mosses. In a quick snapshot, a moss might be mistaken for a lichen. Look for crusts, lobes, or branches, rather than tiny and leafy stems.
3. Ignoring growth form and habitat. Overlooking the growth form and the substrate leaves too many similar possibilities. Observe whether it lies flat, appears wrinkled, or hangs down, and note what it is growing on.

Avoiding these mistakes will help you capture a clearer image and achieve a more accurate identification.

Why Use Botan to Identify Lichens?

Botan helps you identify a lichen from a single photograph. It’s a handy tool to have along on any walk or hike. Here are a few good reasons to use this app:

• The recognition feature works with photos taken using your phone’s camera.
• The app provides suggestions that you can explore in greater detail.
• The straightforward process is easy to follow, even if you have no prior experience with botany.
• If the result seems unclear, you can simply try again by taking a different photo.

Use the result as a starting point, then verify the key characteristics yourself.