Pleurozium schreberi is a moss with a loose growth pattern. The name pleuro comes from the Latin for ribs, possibly describing how the parts branch from the stem.
Pleurozium schreberi (Brid.) Mitt., J. Linn. Soc. Bot. 12: 537. 1869.
An extremely common species that is recognizable in the field by its robust, pinnately branched, red stems with loosely imbricate, concave leaves which are obtuse at the apex and have a short double costa. Commonly known as the red stemmed feather moss.
Grows in prostrate, loose mats, and has a light to yellowish green colour, often brown below, and is fairly glossy. Its stem is 6-15 cm long, notably red, pinnately branched, epidermal cells small and thick walle din cross section. The branches are attenuate, the rhizoids smooth or minutely papillose, sparse, in clusters at base of stems and tips of branhces. The pseudoparaphyllia are foliose, orbicular, sometimes lacking.
Stem leaves are erect, loosely imbricate, somewhat plicate when dry, concave and boat shaped, oblong-ovate, obtuse, apices recurved, shortly decurrent. Branch leaves are similar except apices often abruptly obtuse. Perichaetial leaves sheathing base of seta are lanceolate and acuminate. Th leaf margins are plane, often recurved at the base, broadly incurved above, and crenulate to serrulate at the apex. The costa is double, extending a short distance above the base of the leaf. Leaf cells are smooth, the walls thick, pitted at base. Median cells are fusiform to vermicular, becoming shorter and broader near the apex and base, alar cells are differentiated, ornage, somewhat inflated, quadrate to oblong.
Plants are dioicous, and asexual reproductive bodies are lacking. The calyptrae are cucullate, naked, yellowish with a reddish tip. Capsules are solitary, on setae scattered along stems, brown to reddish brown, oblong-cylindric, arcuate, inclined to horizontal, smooth, wrinkled at neck and contracted under mouth when dry. Setae are straight to somewhat flexuose, smooth, often twisted when dry, and are red in colour. Annuli are lacking, opercula are conic, apiculate, and straight. Peristomes are double, hypnaceous, exostome yellow to brown, endostome hyaline, 2-3 cilia, nodulose. The spores are yellow to yellowish brown, globose, minutely papillose, 10-19 micrometers.
Habitat is on humus and soil in woods, occassionalyl in bogs, sometimes occurring on stumps. Its distribution is cosmopolitan, and is often very common from Greenland to Alaska, south to North Dakota, Colorado, Idaho, and Oregon. Specie's range also extends to South America, Europe and Asia.
Chromosomes number: n= 5, 7
-Robert R. Ireland, Moss Flora of the Maritimes Provinces, Volume II