Gray Reindeer Lichen (Reindeer Moss)

Pale gray cluster of gray reindeer lichen growing in a patch of moss
Scientific Name
Cladina rangiferina (syn. Cladonia rangiferina)
Cladoniaceae (a fruticose lichen family)

Gray reindeer lichen takes the form of bright ashy gray or silvery gray cushions. These much-branching cushions are the reproductive structures (podetia) of the lichen. The branches of reindeer lichens are round in cross-section. The spores are produced in tiny, brownish knobs at the tips of the branches.

Less noticable, the main body of the lichen (thallus) consists of green, scalelike structures (squamules) that spread like a mat over the surface of the soil; these squamules often don’t last long and may be gone by the time the podetia develop.

There are some close relatives (also called reindeer lichens) that look similar, but in gray reindeer lichen, the branches usually end with 3 or 4 tips, and these, at least partly, bend to point in the same direction — as if they were blown by a strong wind, or combed, and froze in that position. Also, there are usually obvious, trunklike, main stalks that give rise to the bushy branching tips.

The cold, silvery gray color reflects the chemical properties of this lichen. Specialists often apply certain chemicals to a sample of a lichen, then watch for color changes, to verify their IDs.

Like many other fruticose lichens, or shrubby lichens, reindeer lichens are three-dimensional, resembling a tiny leafless shrub. Unlike crustose and foliose lichens, which are basically flat or leaflike, fruticose lichens don’t have a distinctive top, middle, and lower layer, since they are like little shrubs or trees. They have a well-developed three-dimensional growth pattern.

Despite some of the common names, lichens are not mosses; in fact, they are not even plants. A lichen is an organism that results when a fungus species and an algae species join together. Although the relationship between the fungus 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: Gray reindeer lichen is one of three Missouri species of reindeer lichens (traditionally placed in genus Cladina). Our other two reindeer lichens are distinguished by overall color and distinct branching patterns:

  • Dixie reindeer lichen (C. subtenuis) is the most common and widespread reindeer lichen species in eastern North America. It mostly branches in relatively narrow Ys (pairs), each branch is rather slender and usually ends in only two tiny, pointed tips, and it’s usually difficult to pick out centralized main stalks (trunklike axes). Compared to other reindeer lichens in our state, it looks more delicate. The overall color — pale yellow green (as opposed to silvery gray or pale greenish gray) — is also important for identification.
  • Tree reindeer lichen (C. arbuscula), like reindeer lichen, is pale yellow green (as opposed to silvery gray or greenish gray). A big difference, however, is that, like gray reindeer lichen, it mostly branches in whorls of 3s or 4s, not Ys or pairs, and it has definite main stalks that give rise to the bushy branching tips.

Many scientists group the various Cladina species in with genus Cladonia. Counting all these “cladoniform” lichens together, Missouri has about 40 species (37 in genus Cladonia plus 3 traditionally placed in genus Cladina). Most of these, at some point in their life cycle, exist as patches of rather unspectacular greenish or grayish, scalelike squamules. The various shapes, colors, and textures of the fruiting bodies are important for identification in this group.

Other Common Names
Reindeer Cup Lichen
Deer Moss

Each cushion may be several inches wide and tall. Cladoniform lichens, as they spread, may cover several square inches of substrate.

Where To Find

Statewide, in appropriate habitats.

Gray reindeer lichen is widespread and common in northern North America and is most common in boreal, tundra, and alpine habitats such as Canadian pine forests and rocky heaths. It almost always grows on soils — usually in dry, sunny, exposed habitats — and it can withstand extremes of both cold and heat.

Gray reindeer lichen grows extremely slowly — only about ½ inch a year, at most — so it takes many years for them to recover in a landscape if they’ve been trampled by people or livestock or are otherwise harmed or destroyed.

Life Cycle

Lichens can reproduce vegetatively or sexually. In reindeer lichens, vegetative (asexual) reproduction is probably most common. It can occur whenever a piece of the lichen breaks away and is moved to another location, where it can begin growing independently elsewhere.

Lichens, especially when dry, may break easily, and the fragments may be transported to new locations via wind or water. The various reindeer lichens, when dry, become very brittle; when, say, a deer steps on one with a muddy hoof, portions of the lichen may easily be dispersed to new locations.

The fungal component of a lichen can reproduce sexually, in the same manner as other fungi: the spores they create are the result of a fusion of gametes (sperm and ova) that occurs in the reproductive structures of the fungus. In this species, these look like tiny brown knobs on the branch tips.

Reindeer lichens are a group that have been used medicinally for a variety of applications. With their chemical properties, they may also be toxic.

Can you eat lichens? Reports vary. Certain types of reindeer lichens, in some parts of the world, have been eaten in the past, especially as a survival food. But many lichens contain toxic chemicals, so we do not recommend eating them. Reportedly, when used as a food, the flavor of reindeer lichens is not worth recommending, anyway.

When dry, shrubby lichens such as these have been used as tinder for starting fires.

Like other lichens, shrubby lichens have been used to make dyes for clothing.

Model railroaders and others who create miniature landscapes often use dried reindeer lichens, colored bright green or perhaps in autumnal colors, to represent trees and shrubs in their dioramas. Flower arrangers also find many decorative uses for them. You can buy them in a variety of colors at craft stores.

Reindeer lichens contribute to a beautiful and interesting landscape.

Because lichens, with their soft, absorbent tissues, are extremely sensitive to pollution, they are good indicators of environmental health.

The sponge-like cladoniform lichens aren’t called reindeer lichens for nothing. Deer and their relatives eat them, especially in winters up north. In northern North America, caribou rely on them for nearly all their winter diet. They dig through the snow to get at them.

Lichen moth caterpillars feed on lichens, and so do lichen grasshoppers, which live in Missouri’s glades. Both the caterpillars and lichen grasshoppers are camouflaged to blend in perfectly with lichen-mottled rocks and soils.

Some species of flying squirrels build nests out of fruticose lichens such as these.

In desert, tundra, and alpine habitats and regions, lichens may be the dominant form of life. It is estimated that 7 percent of Earth’s surface is covered by lichens.

Soil-living lichens are important stabilizers, preventing soil from being washed away by rain or blown by the wind. Although reindeer lichens seem very fragile and only delicately connected to the ground, they and their surrounding community of humble mosses, lichens, and small vascular plants, help heal lands that have been disturbed, including eroded or overgrazed pasture land, or places where a tree has been toppled, and the roots and accompanying soil tipped out of the earth.

Media Gallery
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.

Reviewed On