Alternation of generations is the predominant type of life cycle in plants and algae. In plants both phases are multicellular: the haploid sexual phase – the gametophyte – alternates with a diploid asexual phase – the sporophyte.
Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophytasensu stricto. Bryophyta may also refer to the parent group bryophytes, which comprise liverworts, mosses, and hornworts. Mosses typically form dense green clumps or mats, often in damp or shady locations. The individual plants are usually composed of simple leaves that are generally only one cell thick, attached to a stem that may be branched or unbranched and has only a limited role in conducting water and nutrients. Although some species have conducting tissues, these are generally poorly developed and structurally different from similar tissue found in vascular plants. Mosses do not have seeds and after fertilisation develop sporophytes with unbranched stalks topped with single capsules containing spores. They are typically 0.2–10 cm (0.1–3.9 in) tall, though some species are much larger. Dawsonia, the tallest moss in the world, can grow to 50 cm (20 in) in height. There are approximately 12,000 species.
The Marchantiophyta are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information.
Hornworts are a group of non-vascular Embryophytes constituting the division Anthocerotophyta. The common name refers to the elongated horn-like structure, which is the sporophyte. As in mosses and liverworts, hornworts have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information; the flattened, green plant body of a hornwort is the gametophyte stage of the plant.
Riccia is a genus of liverworts in the order Marchantiales.
A prothallus, or prothallium, is usually the gametophyte stage in the life of a fern or other pteridophyte. Occasionally the term is also used to describe the young gametophyte of a liverwort or peat moss as well. In lichens it refers to the region of the thallus that is free of algae.
Ceratodon purpureus is a dioicous moss with a color ranging from yellow-green to red. The height amounts to 3 centimeters. It is found worldwide, mainly in urban areas and next to roads on dry sand soils. It can grow in a very wide variety of habitats, from polluted highway shoulders and mine tailings to areas recently denuded by wildfire to the bright slopes of Antarctica. Its common names include redshank, purple forkmoss, ceratodon moss, fire moss, and purple horn toothed moss.
Urnula craterium is a species of cup fungus in the family Sarcosomataceae. Appearing in early spring, its distinctive goblet-shaped and dark-colored fruit bodies have earned it the common names crater cup, devil's urn and the gray urn. The asexual (imperfect), or conidial stage of U. craterium is a plant pathogen known as Conoplea globosa, which causes a canker disease of oak and several other hardwood tree species.
Aneura mirabilis is a parasitic species of liverworts in the family Aneuraceae. It was first described in 1933, as Cryptothallus mirabilis. Plants of this species are white as a result of lacking chlorophyll, and their plastids do not differentiate into chloroplasts.
Pellia epiphylla is a species of thallose liverwort. It occurs in North America, Europe, North Africa and parts of Asia. It grows in patches in damp, sheltered places on neutral or acidic substrates. It is common on the banks of rivers, streams and ditches and also grows in wet woodland, marshes and on wet rocks.
Sphagnum palustre, the prairie sphagnum or blunt-leaved bogmoss, is a species of peat moss from the genus Sphagnum, in the family Sphagnaceae. Like other mosses of this type it can soak up water up to the 30-fold amount of its own dry weight thanks to its elastic spiral fibers. S. palustre is rather frequent and is spread almost all over the world. It mainly grows in wet forests and—compared to other specimens of this genus—rarely grows in moors.
Anthoceros agrestis, commonly called field hornwort, is a bryophyte of the family Anthocerotaceae.
Phaeoceros laevis, the smooth hornwort, is a species of hornwort of the genus Phaeoceros. It is commonly found in areas where moisture is plentiful, such as moist soils in fields, the banks of streams and rivers or inundated beneath the surface of the rivers. It grows to a maximum height of about 5 millimetres and the plants are monoecious; the sex organs are visible on the dorsal surface.
Polytrichum juniperinum, commonly known as juniper haircap or juniper polytrichum moss, is an evergreen and perennial species of moss that is widely distributed, growing on every continent including Antarctica.
Calliergon cordifolium is a species of moss in the Calliergonaceae family, commonly known as the calliergon moss or heart-leaved spearmoss. The species is abundant in the right habitat, and grows in marshes and wet woodland, especially woodland of alder (Alnus) or willow (Salix), as well as around streams, ditches and pools. The species grows in tufts among other moss species. Calliergon cordifolium requires a wet environment to grow, and often grows completely submerged in water. It typically prefers lowland, but has been recorded as high as 910 metres (1,000 yd) above sea level in Inverness, Scotland. The species has a circumpolar Boreo-temperate distribution. It is found throughout Europe. It has been recorded in north and central Asia, as well as Turkey and Japan, throughout North America and in New Zealand.
Pogonatum urnigerum is a species of moss in the family Polytrichaceae, commonly called urn haircap. The name comes from "urna" meaning "urn" and "gerere" meaning "to bear" which is believed to be a reference made towards the plant's wide-mouthed capsule. It can be found on gravelly banks or similar habitats and can be identified by the blue tinge to the overall green colour. The stem of this moss is wine red and it has rhizoids that keep the moss anchored to substrates. It is an acrocarpous moss that grows vertically with an archegonium borne at the top of each fertilized female gametophyte shoot which develops an erect sporophyte.
Polytrichum strictum, commonly known as bog haircap moss or strict haircap, is an evergreen and perennial species of moss native to Sphagnum bogs and other moist habitats in temperate climates. It has a circumboreal distribution, and is also found in South America and Antarctica.
Asterella californica is a complex thallic liverwort in the phylum Marchantiophyta. A. californica often grows as colonies of flat rosettes of light green, rigid thalli, with undersides dark wine-red to nearly black. The receptacles are rounded, with four lobes each bearing a single sporangium sheathed by a white tattered skirt. A. californica is dioecious with separate male plants often intermingled with female plants. This species is found throughout California. See Distribution information below. Asterella californica is the commonest species of the three species of Asterella occurring in California; the other two species are A. bolanderi and A. palmeri.
Sphaerocarpos muccilloi is a species of liverwort in the family Sphaerocarpaceae.
Monoclea forsteri is one of the two species in the thallose liverwort family Monocleaceae. It is dioicous with the capsule dehiscing with a single longitudinal slit. Endemic and widely distributed throughout New Zealand, it is also the country's largest thalloid liverwort. Hooker described the species in 1820. The holotype is in the British Museum.
