Editing Moss (section)

===Description===

[[File:Bryum capillare leaf cells.jpg|thumb|left|Chloroplasts (green discs) and accumulated starch granules in cells of ''[[Bryum|Bryum capillare]]'']]

Botanically, mosses are [[non-vascular plant]]s in the land plant division Bryophyta. They are usually small (a few centimeters tall) [[Herbaceous plant|herbaceous]] (non-woody) plants that absorb water and nutrients mainly through their leaves and harvest [[carbon dioxide]] and sunlight to create food by [[photosynthesis]].<ref name=mathews /><ref name=pojar /> With the exception of the ancient group [[Takakia|Takakiopsida]], no known mosses form [[mycorrhiza]],<ref>{{Cite journal|url=https://nph.onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.2009.03137.x|title=Presence of three mycorrhizal genes in the common ancestor of land plants suggests a key role of mycorrhizas in the colonization of land by plants|first1=Bin|last1=Wang|first2=Li Huey|last2=Yeun|first3=Jia-Yu|last3=Xue|first4=Yang|last4=Liu|first5=Jean-Michel|last5=Ané|first6=Yin-Long|last6=Qiu|date=19 December 2010|journal=New Phytologist|volume=186|issue=2|pages=514–525|via=Wiley Online Library|doi=10.1111/j.1469-8137.2009.03137.x|pmid=20059702 |bibcode=2010NewPh.186..514W |hdl=2027.42/78704 |hdl-access=free}}</ref> but bryophilous fungi is widespread in moss and other bryophytes, where they live as saprotrophs, parasites, pathogens and mutualists, some of them [[endophyte]]s.<ref>{{Cite web|url=https://www.duo.uio.no/bitstream/handle/10852/11880/Heimdal.pdf?sequence=3|title=Using 454 sequencing for exploring diversity, host specificity and tissue specificity of the fungal genus Galerina associated with four boreal mosses}}</ref> Mosses differ from [[vascular plants]] in lacking water-bearing [[xylem]] [[tracheids]] or [[vessel elements|vessels]]. As in [[Marchantiophyta|liverworts]] and [[hornwort]]s, the [[haploid]] [[gametophyte]] generation is the dominant phase of the [[biological life cycle|life cycle]]. This contrasts with the pattern in all vascular plants ([[seed plants]] and [[pteridophytes]]), where the [[Haploid|diploid]] [[sporophyte]] generation is dominant. Mosses reproduce using [[spore]]s, not [[seed]]s, and have no flowers.

[[File:Moss leaf under microscope.jpg|thumb|upright=0.9|Moss leaf under microscope, showing [[Gemma (botany)|gemmae]] and a hair point (40x)]]

Moss gametophytes have stems which may be simple or branched and upright (acrocarp) or prostrate (pleurocarp). The early divergent classes Takakiopsida, Sphagnopsida, Andreaeopsida and Andreaeobryopsida either lack [[stoma]]ta or have pseudostomata that do not form pores. In the remaining classes, stomata have been lost more than 60 times.<ref>{{Cite journal|title=With Over 60 Independent Losses, Stomata Are Expendable in Mosses|first1=Karen S.|last1=Renzaglia|first2=William B.|last2=Browning|first3=Amelia|last3=Merced|date=28 May 2020|journal=Frontiers in Plant Science|volume=11|page=567 |doi=10.3389/fpls.2020.00567|doi-access=free |pmid=32547571 |pmc=7270291 |bibcode=2020FrPS...11..567R }}</ref> Their leaves are simple, usually only a single layer of cells with no internal air spaces, often with thicker midribs (nerves). The nerve can run beyond the edge of the leaf tip, termed excurrent. The tip of the leaf blade can be extended as a hair point, made of colourless cells. These appear white against the dark green of the leaves. The edge of the leaf can be smooth or it may have teeth. There may be a distinct type of cell defining the edge of the leaf, distinct in shape and/or colour from the other leaf cells.<ref name="BBS - field guide2010">{{cite book |last1=Atherton |first1=Ian |last2=Bosanquet |first2=Sam |last3=Lawley |first3=Mark |title=Mosses and Liverworts of Britain and Ireland - a field guide |date=2010 |publisher=British Bryological Society |isbn=9780956131010 |pages=848}}</ref>

Moss has threadlike [[rhizoids]] that anchor them to their substrate, comparable to [[root hairs]] rather than the more substantial [[root]] structures of [[spermatophytes]].<ref name="Watson1981">{{cite book |last1=Watson |first1=E. Vernon |title=British Mosses and Liverworts |date=1981 |publisher=Cambridge University Press |isbn=052129472X |pages=519 |edition=3rd}}</ref> Mosses do not absorb water or nutrients from their substrate through their rhizoids.{{citation needed|date=April 2020}} They can be distinguished from [[Marchantiophyta|liverworts]] ([[Marchantiophyta]] or Hepaticae) by their multi-cellular rhizoids. Spore-bearing capsules or [[sporangium|sporangia]] of mosses are borne singly on long, unbranched stems, thereby distinguishing them from the [[polysporangiophytes]], which include all vascular plants. The spore-producing sporophytes (i.e. the [[diploid]] multicellular generation) are short-lived and usually capable of photosynthesis, but are dependent on the gametophyte for water supply and most or all of its nutrients.<ref name=Budke-2018>{{cite journal |first1=Jessica M |last1=Budke |first2=Ernest C |last2=Bernard |first3=Dennis J |last3=Gray |first4=Sanna |last4=Huttunen |first5=Birgit |last5=Piechulla |first6=Robert N |last6=Trigiano |date=2018 |title=Introduction to the special issue on bryophytes |journal=Critical Reviews in Plant Sciences |volume=37 |issue=2–3 |pages=102–112 |doi=10.1080/07352689.2018.1482396 |bibcode=2018CRvPS..37..102B }}</ref> Also, in the majority of mosses, the spore-bearing capsule enlarges and matures after its stalk elongates, while in liverworts the capsule enlarges and matures before its stalk elongates.<ref name=pojar /> Other differences are not universal for all mosses and all liverworts, but the presence of a clearly differentiated stem with simple-shaped, non-vascular leaves that are not arranged in three ranks, all point to the plant being a moss.{{citation needed|date=April 2023}}