Beautiful components of woodland scenery, the overall appearance of broom mosses is lush and cushiony, appearing carpetlike. Our most common broom mosses have glossy, thin, slender-pointed leaves that are quite long and all bend in the same direction, as if being blown by the wind. Sometimes the leaves are wavy, like crisped bacon. Broom mosses may range from a yellowish green to a darker, though still vibrant green.
Older plants are much-branched and somewhat spreading, but they are so compacted as to remain in an upright positions, forming dense tufts or mats. Among the stalks in a single colony, the height or thickness of the stems varies considerably; this wavy look creates areas of shadow and light that give broom mosses a soft, shimmery appearance.
The capsules are slender, borne on relatively long stalks, and are erect to slightly inclined. The capsule stalks arise from the moss's stem tips.
Learn more about Missouri’s mosses on their group page.
Four species in genus Dicranum are recorded for Missouri:
- D. scoparium, the windswept broom moss or broom forkmoss, is the most common broom moss in Missouri. Its most obvious character is the windswept look of its lanceolate leaves with long, pointed tips. It is a characteristic plant in Missouri’s igneous talus natural communities, located in the eastern Ozarks.
- D. spurium, the rusty forkmoss, is dull greenish or brown and changes its look drastically when dry, as the leaf tips curl and contort. When moist, the leaves spread out again. It has wider leaves than D. condensatum, and the leaves are widest near the middle of the leaf instead of at the base. In our state, it prefers granite, sandstone, or dolomite ledges; it also sometimes occurs on acidic soils on ridges.
- D. condensatum, the condensed dicranum moss, is a dull light green to yellowish brown. It has narrower leaves than D. spurium, and the leaves are widest at the base. It lives on rocky and sandy soil, decaying wood, and rock crevices and ledges.
- D. polysetum, the wavy broom moss, is a species of conservation concern in our state, found only in limited locations in southwest Missouri. It is light green, and its stems are densely covered with a whitish or reddish fuzz (filamentous rhizoids). The stems may be nearly 6 inches long.
A closer look: The genus name, Dicranum, comes from the Greek word dicranon, which means “pitchfork.” The name refers to the 16 forked teeth in the opening of the capsule. To be precise: the capsules have an opening at the tip from which the spores are shed. The opening is guarded by the peristome, a set of teeth that encircle the opening; they can open or close to regulate spore release, depending on moisture level. In the case of broom mosses, the peristome consists of 16 teeth that are split one-third to one-half of their length into 2 divisions. Magnified, they look something like a ring of narrow triangles that each are split at the top to form a pair of filaments.
Height: varies with species. The stems of C. scoparium, our most common species, may be 2–3 inches high.
Statewide. Different species have different distribution patterns.
Habitat and Conservation
Broom mosses occur mainly on soil, especially along ridges and wooded slopes, but they may also be found on rocks and rock ledges, rotten wood, or the bases and trunks of trees.
Status
One species in this group, the wavy broom moss (Dicranum polysetum), is a species of conservation concern in Missouri and is ranked as critically imperiled.
Life Cycle
As with other mosses, broom mosses have alternating generations. The plant we usually think of as the moss is the gametophyte generation (it’s a gamete-, or sex-cell-bearing plant). In separate organs, it produces sperm and eggs. When water, even a thin layer of rainwater, is present, the sperm can swim to the eggs and fertilization occurs. The resulting offspring plant, called a sporophyte (spore-bearing plant), grows out of the female organs of the gametophyte.
In broom mosses, the sporophyte takes the form of a stalked capsule growing out of the tip of the gametophyte stem. It obtains nutrients from the gametophyte. When mature, the capsule opens to release spores, which can grow into new gametophyte plants.
Mosses also commonly reproduce asexually when a portion of the plant breaks away, gets moved elsewhere, and continues growing as a separate plant.
Human Connections
Certain hardy, widespread species of broom mosses, with their deep green color and soft, pettable texture, are among the most popular mosses cultivated by moss gardeners.
The windswept broom moss, our most common species, is easy to identify once you get an idea of its tapering, pointed leaves and its “windswept look.”
Ecosystem Connections
The carpets and mats formed by mosses and other small plants form a microhabitat where many types of insects and other invertebrates live. Earthworms, centipedes, sowbugs, springtails, snails, and a wide variety of other small animals live in and around mosses. Tartigrades, or water bears, are curious microscopic eight-legged animals that often live among mosses. Shrews, salamanders, frogs, tiny snakes, and other insectivores hunt for a variety of small animals among the mosses.
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.