[4] Mosses were formerly grouped with the hornworts and liverworts as "non-vascular" plants in the division "bryophytes", all of them having the haploid gametophyte generation as the dominant phase of the life cycle.
Moss can be a troublesome weed in containerized nursery operations and greenhouses.
Up to the Kingdom.
Moss, (division Bryophyta), any of at least 12,000 species of small nonvascular spore-bearing land plants. In most genera the capsules have peristome teeth.
[44] In Mexico, Moss is used as a Christmas decoration. Andreaeopsida and Andreaeobryopsida are distinguished by the biseriate (two rows of cells) rhizoids, multiseriate (many rows of cells) protonema, and sporangium that splits along longitudinal lines.
but by disintegration in a very few genera.
Aside from this character, the unique branching, thallose (flat and expanded) protonema, and explosively rupturing sporangium place it apart from other mosses. Most members of the Bryopsida have spore capsules with peristome teeth. Also, in most mosses, the spore-bearing capsule enlarges and matures after its stalk elongates, while in liverworts the capsule enlarges and matures before its stalk elongates.
[6] Such aquatic or semi-aquatic mosses can greatly exceed the normal range of lengths seen in terrestrial mosses. Stems of some aquatic mosses can be quite long, but the Polytrichales are terrestrial mosses with free-standing stems. A single mat of protonemata may develop several gametophore shoots, resulting in a clump of moss. The following is a list of some of the major genera and species of mosses, arranged alphabetically by common name. Class Bryopsida – True mosses. The spore-bearing sporophytes (i.e.
Subdivision Musci. In the field, most Sphagnum species can be identified to one of four major sections of the genus—classification and desc…
[29], The capacity of dried mosses to absorb fluids has made their use practical in both medical and culinary uses.
Botanically, mosses are non-vascular plants in the land plant division Bryophyta. Food storage baskets and boiling baskets were also packed with mosses.[29].
This article was most recently revised and updated by, https://www.britannica.com/plant/moss-plant, Te Ara - The Encyclopedia of New Zealand - Mosses, moss - Children's Encyclopedia (Ages 8-11), moss - Student Encyclopedia (Ages 11 and up). [29] Tribes of the Pacific Northwest in the United States and Canada used mosses to clean salmon prior to drying it, and packed wet moss into pit ovens for steaming camas bulbs. Capsule raised on a pseudopodium. Muscites, Protosphagnum, Palaeohypnum, and other fossil mosses are similar in structure to modern genera.
The main commercial significance of mosses is as the main constituent of peat (mostly the genus Sphagnum), although they are also used for decorative purposes, such as in gardens and in the florist trade. class: Andreaeopsida Irish moss (Chondrus crispus) is a red alga.
Notice that everyone agrees that the "Takakia" and "Sphagnum" groups are markedly different from all other bryophytes. capsule with hair-like peristome teeth.
It grows in both hot and cold climates in well-drained, open environments. The weathered rocks also released a lot of phosphorus and iron which ended up in the oceans, where it caused massive algal blooms, resulting in organic carbon burial, extracting more carbon dioxide from the atmosphere. The uses for intact moss are principally in the florist trade and for home decoration. In Gemmabryum dichotomum the teeth are well-developed but in Tayloria gunnii they are rather small.
This page was last edited on 13 October 2020, at 21:09. From the tips of the gametophore stems or branches develop the sex organs of the mosses. Interestingly, in the 2000 classification the family Diphysciaceae was placed in the order Diphysciales within the class Bryopsida.
Most mosses rely on the wind to disperse the spores. Ultimately, the gametophyte grows from a small bud produced by a cell of the protonema that divides and differentiates. Bryophytes are now split into three divisions: Bryophyta, Marchantiophyta and Anthocerotophyta. perigonia). Here is a close-up of one tooth. Peristome teeth nematodontous.
class: Takakiopsida Capsule raised on a seta that is composed of sporophyte tissue. The sporophytic (asexual) generation develops from the gametophyte and usually consists of a raised stalk, or seta, which terminates in the sporangium. The sporangium remains dependent on the gametophyte, to varying degrees, for water and nutrients.
archegonium) and are protected by a group of modified leaves known as the perichaetum (plural, perichaeta).
Mosses are commonly confused with hornworts, liverworts and lichens. – fissidens moss P. Species Fissidens ventricosus Lesq. This is a transitory stage in the life of a moss, but from the protonema grows the gametophore ("gamete-bearer") that is structurally differentiated into stems and leaves. class: Andreaeobryopsida
The debate is about whether those two groups warrant separate divisions. Many mosses can survive desiccation, sometimes for months, returning to life within a few hours of rehydration.[29].
Baby Tooth Moss.
In this case, grass is considered to be the weed. The moss life-cycle starts with a haploid spore that germinates to produce a protonema (pl. The majority of mosses have arthrodontous peristome teeth and an example of an arthrodontous peristome is shown in the accompanying photo.
Order Hypnales.
Get exclusive access to content from our 1768 First Edition with your subscription. By signing up for this email, you are agreeing to news, offers, and information from Encyclopaedia Britannica. Prominent examples are the identification of moss genes
each chromosome has a partner that contains the same, or similar, genetic information. Capsule raised on a pseudopodium. Be on the lookout for your Britannica newsletter to get trusted stories delivered right to your inbox. Let us know if you have suggestions to improve this article (requires login).
[3] Mosses do not have seeds and after fertilisation develop sporophytes with unbranched stalks topped with single capsules containing spores.
If this occurs during meiosis (part of sexual reproduction), they could become infertile. However, this definition of Bryophyta was paraphyletic, as the mosses appear to be more closely related to vascular plants than to liverworts.
Arthrodontous peristome teeth have considerable flexibility and can curl or uncurl in response to changes in humidity. Flies attracted to the moss carry its spores to fresh herbivore dung, which is the favoured habitat of the species of this genus.[12]. The genome of P. patens has been sequenced, which has allowed several genes involved in DNA repair to be identified. It's not surprising that most of the mosses people come across belong to the class Bryopsida. [26], Recent research shows that ancient moss could explain why the Ordovician ice ages occurred. order: Tetraphidales (3 families, 4 genera, no more than about 50 species). Articles from Britannica Encyclopedias for elementary and high school students.
However, specific species of moss can be extremely difficult to maintain away from their natural sites with their unique requirements of combinations of light, humidity, substrate chemistry, shelter from wind, etc. Capsule opens along several vertical dehiscence lines. "Morphology and classification of mosses", pages 71-123, "Conducting tissues and phyletic relationships of bryophytes", "Microarthropods Mediate Sperm Transfer in Mosses", "Sexual dimorphism in the Japanese species of Macromitrium Brid. [31], In boreal forests, some species of moss play an important role in providing nitrogen for the ecosystem due to their relationship with nitrogen-fixing cyanobacteria.
Moss growth can be inhibited by a number of methods: The application of products containing ferrous sulfate or ferrous ammonium sulfate will kill moss; these ingredients are typically in commercial moss control products and fertilizers. Capsule generally opens by means of an operculum,
They are best known for those species that carpet woodland and forest floors.