Hypnum

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Hypnum
Hypnum cupressiforme
Scientific classification Edit this classification
Kingdom: Plantae
Division: Bryophyta
Class: Bryopsida
Subclass: Bryidae
Order: Hypnales
Family: Hypnaceae
Genus: Hypnum
Hedw.

Hypnum is a genus of mosses belonging to the family Hypnaceae.[1]

The genus has cosmopolitan distribution.[1] A common name sometimes used for Hypnum moss is "carpet moss".[2]

Distribution[edit]

Hypnum species are found on all continents except for Antarctica.[3] Species are typically found in temperate regions.[3]

Habitat[edit]

Hypnum species are typically found in moist forest areas on rotting logs, while some species are aquatic.[2][4] Species can also be found living on soil, rocks, and live trees.[4]

Identification[edit]

Identifying moss species in the field to the genus Hypnum by using a hand lens is considered quite feasible since most Hypnum species share common features with one another.[3] A very useful defining characteristic of Hypnum mosses are their leaves which are often falcate-secund (meaning that they are sickle-shaped and point to one side of the plant).[3] Another distinguishing characteristic of Hypnum mosses is the thick, green mats that they form, which earns them the common name "carpet moss".[2] Distinguishing between different Hypnum species can be accomplished mainly by gametophytic features and sometimes by sporophytic features.[3]

Description[edit]

Gametophyte characteristics[edit]

General form[edit]

Gametophytes range from small to large in size.[3] Gametophytes are green, yellowish, or brown in colour, with the colouration appearing dull or glossy.[3] Gametophytes can sometimes form tufts.[3] Growth forms of Hypnum mosses vary from creeping to erect.[5]

Stem and branching patterns[edit]

Stems have pseudoparaphyllia.[3] Branching patterns include nearly unbranched, irregularly branched, or 1- or 2- times pinnate.[5][3]

Leaves[edit]

Branch leaves and stem leaves have similar shapes.[5] Leaves are secund or falcate-secund, broadly to narrowly ovate, and can be plicate.[3] Leaf bases can sometimes be decurrent.[3] Sometimes leaf margins are toothed on the distal region.[3] Leaf margins can be recurved proximally and are usually flat (i.e., not recurved) at the distal edge.[3] Leaf margins can sometimes be sinuate at the proximal region.[3] Leaf apices are either acute or acuminate.[3]

Despite having similar shapes, branch leaves are smaller than stem leaves.[5]

Leaves have a double costa or an obscure costa that spans 1/4 of the leaf's length.[3] Laminal cells are exclusively smooth.[3] Alar cells in the leaf bases are typically differentiated and range in shape from hexagonal, triangular, quadrate, or sub-quadrate.[3]

The outer perichaetial leaves are bent while the inner perichaetial leaves are erect.[3] In terms of shape, perichaetial leaves can be ovate, lanceolate, or subulate.[3] Apices of perichaetial leaves are acuminate.[3]

Calyptra[edit]

Calyptra are exclusively naked and have no hair.[3]

Sporophyte characteristics[edit]

Seta[edit]

Setae are long and range in colour from yellowish to reddish.[5][3]

Sporangium[edit]

Orientation of the sporangium can be erect, inclined, or horizontal.[5][3] Sporangium shape varies from cylindrical to ovoid.[5] The sporangium is also typically curved.[3] There tends to be a contraction below the sporangium opening.[3] All species have two rows of peristome teeth.[3] The outer surface of exostome teeth have zigzag lines as well as lamellae.[3] The annulus is either 1-3- times seriate or has very minimal amounts of cell differentiation.[3] The operculum is conical to round in shape.[3]

Spores produced by the sporangium are round and can be smooth or papillose in texture.[3]

Reproduction[edit]

In terms of sexual reproduction, Hypnum mosses are autoicous, dioicous, or phyllodioicous.[3] Hypnum mosses do not have any specialized forms of asexual reproduction.[3]

Human use[edit]

Historically, Hypnum mosses were used to stuff bedding because they were falsely believed to have sleep-inducing properties.[2][3]

Hypnum curvifolium, commonly known as "sheet moss", is used by some florists.[6]

The CityTree air filter, present in many European cities, uses Hypnum to capture and consume pollutants.[7]

Species[edit]

The number of species in the genus is unresolved. Depending on the source, the number of species ranges from around 50 to 220,[3][5] or (according to GBIF) up to 773.[8]

Some of the species in the genus are:

Former species[edit]

References[edit]

  1. ^ a b c d "Hypnum Hedw". www.gbif.org. Retrieved 22 February 2021.
  2. ^ a b c d "carpet moss | Description & Facts | Britannica". www.britannica.com. Retrieved 2022-05-01.
  3. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj "Hypnum in Flora of North America @ efloras.org". www.efloras.org. Retrieved 2022-05-01.
  4. ^ a b "Hypnum moss (Hypnum cuppressiforme) – life4oakforests.eu". Retrieved 2022-05-01.
  5. ^ a b c d e f g h Allaby, Michael (2013-04-18), "Hypnum", A Dictionary of Plant Sciences, Oxford University Press, doi:10.1093/acref/9780199600571.001.0001/acref-9780199600571-e-3413, ISBN 978-0-19-960057-1, retrieved 2022-04-07
  6. ^ "sheet moss | Description & Facts | Britannica". www.britannica.com. Retrieved 2022-05-01.
  7. ^ O'Donoghue, J. J.; O'Byrne, Ellie (2021-08-11). "Everything you wanted to know about Cork's new Robo-trees but were afraid to ask". Tripe + Drisheen. Retrieved 2023-12-26.
  8. ^ "Hypnum Hedw". www.gbif.org. Retrieved 15 September 2022.
  9. ^ a b c "Hypnum Hedw". www.gbif.org. Retrieved 2022-04-07.
  10. ^ "Hypnum Hedw". www.gbif.org. Retrieved 2022-05-01.
  11. ^ a b Cao, Wei; Xiong, Yuanxin; Zhao, Degang; Tan, Hongying; Qu, Jiaojiao (January 2020). "Bryophytes and the symbiotic microorganisms, the pioneers of vegetation restoration in karst rocky desertification areas in southwestern China". Appl Microbiol Biotechnol. 104 (2): 873–891. doi:10.1007/s00253-019-10235-0. PMC 6943408.
  12. ^ "Hypnum leptothallum (Müll.Hal.) Paris". www.gbif.org. Retrieved 15 September 2022.