A gametophyte is one of the two alternating multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes. The gametophyte is the sexual phase in the life cycle of plants and algae. It develops sex organs that produce gametes, haploid sex cells that participate in fertilization to form a diploid zygote which has a double set of chromosomes. Cell division of the zygote results in a new diploid multicellular organism, the second stage in the life cycle known as the sporophyte. The sporophyte can produce haploid spores by meiosis that on germination produce a new generation of gametophytes.
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.
Bryophytes are a group of land plants, sometimes treated as a taxonomic division, that contains three groups of non-vascular land plants (embryophytes): the liverworts, hornworts and mosses. In the strict sense, Bryophyta consists of the mosses only. Bryophytes are characteristically limited in size and prefer moist habitats although they can survive in drier environments. The bryophytes consist of about 20,000 plant species. Bryophytes produce enclosed reproductive structures, but they do not produce flowers or seeds. They reproduce sexually by spores and asexually by fragmentation or the production of gemmae. Though bryophytes were considered a paraphyletic group in recent years, almost all of the most recent phylogenetic evidence supports the monophyly of this group, as originally classified by Wilhelm Schimper in 1879. The term bryophyte comes from Ancient Greek βρύον (brúon) 'tree moss, liverwort', and φυτόν (phutón) 'plant'.
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.
Monoicy is a sexual system in haploid plants where both sperm and eggs are produced on the same gametophyte, in contrast with dioicy, where each gametophyte produces only sperm or eggs but never both. Both monoicous and dioicous gametophytes produce gametes in gametangia by mitosis rather than meiosis, so that sperm and eggs are genetically identical with their parent gametophyte.
Buxbaumia is a genus of twelve species of moss (Bryophyta). It was first named in 1742 by Albrecht von Haller and later brought into modern botanical nomenclature in 1801 by Johann Hedwig to commemorate Johann Christian Buxbaum, a German physician and botanist who discovered the moss in 1712 at the mouth of the Volga River. The moss is microscopic for most of its existence, and plants are noticeable only after they begin to produce their reproductive structures. The asymmetrical spore capsule has a distinctive shape and structure, some features of which appear to be transitional from those in primitive mosses to most modern mosses.
Plant reproduction is the production of new offspring in plants, which can be accomplished by sexual or asexual reproduction. Sexual reproduction produces offspring by the fusion of gametes, resulting in offspring genetically different from either parent. Asexual reproduction produces new individuals without the fusion of gametes, resulting in clonal plants that are genetically identical to the parent plant and each other, unless mutations occur.
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete with a single set of chromosomes combines with another gamete to produce a zygote that develops into an organism composed of cells with two sets of chromosomes (diploid). This is typical in animals, though the number of chromosome sets and how that number changes in sexual reproduction varies, especially among plants, fungi, and other eukaryotes.
Itatiella ulei is a species of moss in the family Polytrichaceae. It is the only species in the genus Itatiella. The Polytrichaceae is a common family of mosses that does not have close living relatives. Its small size and the inflexed leaf apex characterize Itatiella ulei. When this species grows directly exposed to sun at high elevations, it presents a similar aspect but can be distinguished based on the distal lamella cells which are single and rhombic.
Tetraphis pellucida, the pellucid four-tooth moss, is one of two species of moss in the acrocarpous genus Tetraphis. Its name refers to its four large peristome teeth found on the sporophyte capsule.
Splachnaceae is a family of mosses, containing around 70 species in 6 genera. Around half of those species are entomophilous, using insects to disperse their spores, a characteristic found in no other seedless land plants.
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.
Climacium dendroides, also known as tree climacium moss, belongs in the order Hypnales and family Climaciaceae, in class Bryopsida and subclass Bryidae. It is identified as a "tree moss" due to its distinctive morphological features, and has four species identified across the Northern Hemisphere. The species name "dendroides" describes the tree-like morphology of the plant, and its genus name came from the structure of the perforations of peristome teeth. This plant was identified by Weber and Mohr in 1804. They often have stems that are around 2-10 cm tall and growing in the form of patches, looking like small palm-trees. They have yellow-green branches at the tip of stems. The leaves are around 2.5-3 mm long, with rounder stem leaves and pointier branch leaves. Their sporophytes are only abundant in late winter and early spring, and appears as a red-brown shoot with long stalk and cylindrical capsules.
Fissidens limbatus commonly known as Herzog's pocket-moss, is a moss in the family Fissidentaceae. This species is found growing in high elevations in tropical America in addition to the US, Mexico and Canada. Montagne first collected F. crispus in 1838.
Ulota is a genus of mosses comprising 69 species with a worldwide distribution, though most species are found in the southern hemisphere.
Andreaea rupestris is a species of moss in the class Andreaeopsida, are commonly referred to as the "lantern mosses" due to the appearance of their dehisced sporangia. It is typically found on smooth, acidic, exposed rock in the Northern hemisphere. It exhibits the common features of the genus Andreaea such as being acrocarpous, having dark pigmentation, lacking a seta, and bearing 4 lines of dehiscence in its mature sporangia, but can be further identified upon careful examination of its gametophytic leaves which have an ovate base to a more blunt apex compared to other similar species.
Tortula muralis, commonly known as wall-screw moss, is a species of moss in the family Pottiaceae. T. muralis is found throughout the world.
Polytrichastrum formosum, commonly known as the bank haircap moss, is a species of moss belonging to the family Polytrichaceae.
Andreaea blyttii, also commonly known as Blytt's rock moss, is a moss belonging to the family Andreaeaceae, commonly known as rock moss, granite moss, or lantern moss because of this family's unique sporangium. It is part of the genus Andreaea which is known for forming dark brownish or reddish-black carpets in high elevations. This species was first described by Schimper in 1855.
Dicranoloma billardierei is a species of bryophyte in the genus Dicranoloma. This moss is extremely common in wet rainforest habitats. In the field, Dicranoloma billardierei, is often confused with Dicranoloma robustum and Dicranoloma fasciatum. However, the short and obtuse nature of the leaves make this moss normally very distinctive.
