Ceratodon purpureus

Fire moss is a short moss that forms dense tufts or sometimes cushions. The stems are erect, usually about 0.5 inch (1.3 cm) long. The upper 0.19 inch (0.5 cm) is current year's growth; The stems sometimes become 2.4 to 3.1 inches (7–8 cm) long in shaded places. Leaves are short and hairlike, spreading when moist; somewhat folded or twisted when dry. Leaf pigment varies from green to ginger. ==Distribution and habitat==

Fire moss likely occurs in every country but is possibly replaced by closely related taxa in tropical latitudes. It is widespread throughout Canada, where it occurs in every province and territory. It is common in urban and industrial environments subjected to a variety of pollutants, along highways, and on the tailings and refuse associated with both coal and heavy-metal mining activities. Fire moss is often found on disturbed sites. It occurs on a wide range of substrates including soil, rock, wood, humus, old roofs, sand, and cracks of sidewalks. It is most abundant on exposed, compact, mineral, dry, gravelly or sandy soils but tolerates a wide range of soil textures. Sand dunes close to water in Scotland are colonized by fire moss, which grows between the shoots of grasses. ==Life cycle==

Fire moss is dioecious, Usually the setae are present in great numbers in the colony; with changes in humidity they twist and untwist. This movement helps to jerk the capsules, helping in spore discharge. Possibly the contraction of the grooves in the capsule at maturity also helps to squeeze out the spores. Fire moss sporophytes appear early in the spring, as soon as the snow melts. Female plants emit more compounds than male plants. Springtails were found to choose female plants preferentially, and the study found that the springtails enhance moss fertilization. The results seem to suggest a plant-pollinator relationship analogous to those found in flowering plants. ==Ecology==

Fire moss prefers low competition and high light; however, it is somewhat shade tolerant, and has, for example, been reported to grow in artificially illuminated caves. It is a colonizer of disturbed sites and readily invades mineral soil by spores. Fire moss is typically found associated with other species characteristic of disturbed sites such as fireweed (Epilobium angustifolium) and pearly everlasting (Anaphalis margaritacea). Fire moss is often replaced by flowering plants in later stages of succession. Fire moss will colonize burned areas through lightweight, off-site, wind-dispersed spores. High-severity fire, which exposes mineral soil, provides ideal conditions for the germination of fire moss spores. Fire moss is often the dominant vegetation for several years following high-severity fire. It produces few spores late in the first postfire year and many in the second. If fire takes place in early spring; gametophores can develop in 4 to 5 months. If the fire takes place in the fall, colonization is slower. ==References==