Common Script Lichen

Common script lichen growing on a small hickory tree at Painted Rock CA
Scientific Name
Graphis scripta
Graphidaceae (script lichens)

The common script lichen is one of many Missouri crustose lichens. Instead of forming button or wart-shaped reproductive structures, however, the common script lichen produces spores in minute, branching cracks that look like tiny, strange writing. It’s easy to imagine these could be the poems of little elves.

Like other crustose lichens, the common script lichen is tightly attached to its substrate. This species looks like a thin, pale gray or greenish-gray splotch of flat paint that has a cluster of tiny, branching, squiggly, dark lines, which can look like cracks in the surface of the lichen (or like handwriting, hence the common and scientific names).

A lichen is an organism that results when a fungus species and an algae species join together. Although the relationship between the fungi and algae is quite intimate and integrated, the lichen that is formed does not much resemble either of the components. Learn more about lichens on their group page.

Similar species:

  • Some other Missouri genera are considered script lichens, too, including four species of Opegrapha. They look somewhat different from common script lichen, but you can see a resemblance in their grooved or scarlike apothecia.
  • Most members of the script lichen family (Graphidaceae) are tropical, and most live as epiphytes on plants, including tree trunks.
Other Common Names
Secret Writing Lichen

Lichens begin as tiny spots but may grow to cover several square inches. Groups of common script lichens may coalesce to cover large areas.

Where To Find


The common script lichen usually grows on trees that have tight, smooth bark. Shagbark hickories very commonly have script lichens growing on them. Once you are familiar with the look of common script lichen, it will be hard not to see them as you gaze through an open woodland with plenty of young hickory trees. Look for rounded patches on bark that are lighter gray than the rest of the trunk. Lichens do not harm the trees they live on.

Lichens living on tree trunks contribute to the beauty of a wooded landscape. Imagine how dull the woods would look if all the lichens weren’t there!

This is one of the crustose lichens that’s very easy to identify. It’s also easy to overlook; you might have been seeing this lichen your whole life, and not realized what it is.

The scrawly patterns of this lichen’s apothecia really can inspire imagination. Are these the tiny poems or runes of magical woodland beings?

The common script lichen has at least two species of parasitic fungi that are specially adapted to live on it. Such fungi are called lichenicolous fungi and are not technically part of the lichen.

While you’re looking at lichens on trees, notice how other lichens, mosses, and leafy liverworts often avoid overlapping each other. The same thing happens with sessile organisms (ones that must cling to a surface) crowded together in coral reefs: among barnacles, mussels, tubeworms, anemones, urchins, sea stars, and sponges, territory is also at a premium.

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Similar Species
About Mosses, Liverworts, and Lichens in Missouri

Mosses, liverworts, hornworts, and lichens seem rather similar, but these organisms are in very different groups. Mosses, liverworts, and hornworts are small, low plants usually found in damp habitats. Unlike more familiar plants, they lack veinlike structures and do not produce flowers or seeds — instead, they produce spores. Meanwhile, lichens are not plants at all: they are a collection of different fungi that have photosynthetic algae living within their tissues.

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