In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, fungi and protozoa.
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.
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 Embryophyta, or land plants, are the most familiar group of green plants that comprise vegetation on Earth. Embryophytes have a common ancestor with green algae, having emerged within the Phragmoplastophyta clade of green algae as sister of the Zygnematophyceae. The Embryophyta consist of the bryophytes plus the polysporangiophytes. Living embryophytes therefore include hornworts, liverworts, mosses, lycophytes, ferns, gymnosperms and flowering plants. The land plants have diplobiontic life cycles and it is accepted now that they emerged from freshwater, multi-celled algae.
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.
Non-vascular plants are plants without a vascular system consisting of xylem and phloem. Instead, they may possess simpler tissues that have specialized functions for the internal transport of water.
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.
The Funariidae are a widespread group of mosses in class Bryopsida. The majority of species belong to the genera Funaria and Physcomitrium.
Tayloria is a genus of mosses in the family Splachnaceae. It comprises 45 species, divided among 6 subgenera:
Splachnum sphaericum, also known as pinkstink dung moss, is a species of moss. This species occurs in North America. It also occurs in upland Britain, where it is known as round-fruited collar-moss and in north temperate and boreal regions of Europe. Its habitat is bog and wet heathland where it grows on herbivore dung. This and other Splachnum species are entomophilous. The sporophytes, which are generally coloured red or black, produce an odour of carrion that is attractive to flies and the spores are dispersed by flies to fresh dung.
Hypnodendron comosum, commonly known as palm moss or palm tree moss, is a ground moss which can be divided into two varieties: Hypnodendron comosum var. comosum and Hypnodendron comosum var. sieberi. Both Hypnodendron varieties most commonly grow in damp locations in the temperate and tropical rainforests of New South Wales, Victoria, and Tasmania in southern Australia 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.
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.
Splachnum, also known as dung moss or petticoat moss, is a genus of moss that is well known for its entomophily. It commonly grows on patches of dung or decomposing animal matter.
Buxbaumia viridis, also known as the green shield-moss, is a rare bryophyte found sporadically throughout the northern hemisphere. The gametophyte of this moss is not macroscopically visible; the large, distinct sporophyte of B. viridis is the only identifying structure of this moss. This moss can be found singularly or in small groups on decaying wood, mostly in humid, sub-alpine to alpine Picea abies, Abies alba, or mixed tree forests. This moss is rare and conservation efforts are being made in most countries B. viridis is found in.
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.
Splachnum rubrum, is a species of moss in the Splachnum genus which is found in the Northern Hemisphere. Like other species in the Splachnum genus, it is known for growing on animal waste and being entomophilous. Although very rare, its bright red-purple sporangia makes its sporophyte stage stand out well when seenin the wild.
