Polytrichastrum formosum

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Polytrichastrum formosum
Polytrichum formosum 106670343.jpg
Status TNC G5.svg
Secure  (NatureServe) [1]
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Division: Bryophyta
Class: Polytrichopsida
Order: Polytrichales
Family: Polytrichaceae
Genus: Polytrichastrum
Species:
P. formosum
Binomial name
Polytrichastrum formosum
(Hedw.) G.L. Smith

Polytrichastrum formosum, commonly known as the bank haircap moss, [2] is a species of moss belonging to the family Polytrichaceae.

Contents

It has a cosmopolitan distribution, found mostly in temperate latitudes in the Northern Hemisphere [3] and especially dominant in Europe and North America. However, it has also been identified in India, China, Nepal, Japan, Algeria, Australia, New Zealand, Russia, Turkey, Syria, and the Atlantic islands (i.e. Iceland). [3] [4] [5]

This species was previously called Polytrichum formosum but has been reclassified as Polytrichastrum formosum due to distinct sporangial features. [6] Recent molecular studies suggest that it should be moved back to its original genus (Polytrichum), [7] however bryologists have not yet reached a consensus.  

Habitat

Polytrichastrum formosum generally inhabits shaded, poor soils and humus in damp coniferous forests and cool temperate rainforests. [3] [8] This species is most common in Europe and grows in grasslands, lowland heaths, acidic moorlands, rocky slopes, and old buildings. [5]

Gametophyte

Like all moss, the haploid gametophyte is the dominant phase of the lifecycle of P. formosum. The moss gametophyte has photosynthetic leaves, a stem, and root-like rhizoids that anchor them to the substrate. [9]

Polytrichastrum formosum is a medium to large robust acrocarpous moss, growing in uncrowded, unbranching tufts. [2] [3] Its colour ranges from green to dark olive green to greenish black. The stems of mature plants are generally 3 to 8 cm tall, however they can be as short as 2 cm or as tall as 20 cm. [3] P. formosum, like all members of Polytrichaceae, is an endohydric moss, meaning water conduction occurs internally. [10] This process is made possible by a central conducting strand in the stem, made up of hydroids, which are cells specialized for water transport. [11] [12] The stem also contains leptoids and specialized parenchyma cells that are used for conducting sugars throughout the plant. [12] The hydrome (made of hydroids) and leptome (made of leptoids) are considered analogous in function to xylem and phloem in vascular plants. [10] For structural support there are also thick-walled stereid cells circling the hydrome, which helps the moss grow tall. [10]

Ventral surface of a leaf from P. formosum. Polytrichum formosum (k, 144735-474752) 6720.JPG
Ventral surface of a leaf from P. formosum.

The leaves of Polytrichastrum formosum are linear-lanceolate, and are usually 6 to 8 mm in length, but can be up to 12 mm long. [3] They are erect to spreading when the moss is dry but become broadly recurved when moist. [3] The leaves have a toothed margin and a prominent costa, where guide cells help conduct water throughout the leaf, and stereids on the dorsal side provide protection. [3] [13]

Cross-section of P. formosum leaf, revealing photosynthetic lamellae. Polytrichastrum formosum (g, 144932-481517) 3305.JPG
Cross-section of P. formosum leaf, revealing photosynthetic lamellae.

Using a microscope, photosynthetic lamellae are visible in cross section, nearly covering the entire ventral surface of the leaf. [2] [3] A feature unique to Polytrichaceae, lamellae are often compared to the mesophyll of vascular plants due to their role in photosynthesis. [14] Each lamella stands 3 to 7 cells high and the cells at the top are smooth and oblong. [2] [3] Lamellae help increase desiccation tolerance and photosynthetic efficiency by providing more surface area for light absorption and gas exchange. [13] [15] The lamellae are covered by a layer of hydrophobic wax that protects the air spaces between neighbouring lamella from being flooded with water, which would impede CO2 uptake necessary for photosynthesis. [16] [14] In this way, P. formosum is able withstand high irradiance better than other mosses.

Sporophyte

P. formosum angled sporophyte capsules (calyptra absent). Polytrichastrum formosum (a, 145137-481315) 6354.jpg
P. formosum angled sporophyte capsules (calyptra absent).

The diploid sporophyte generation of P. formosum matures in early summer and is short-lived. [5] The solitary sporophyte grows out of the female gametophyte, relying on it for energy and nutrients. It is anchored to the gametophyte by a foot, and has a stalk (seta) elevating a capsule (sporangia) in which spores will develop via meiosis. [17] The seta is yellowish to reddish brown and is 3 to 6 cm tall. [3] Like the stem of the gametophyte, the seta has a hydrome and leptome for conducting water and sugars from the gametophyte. [17] The slender and short-rectangular capsule is ochre to brown and 4 to 7 mm long. [3] The capsule is terete or 4-6 angled, which distinguishes Polytrichastrum species from Polytrichum species. [6] In the early stages of growth the capsule is covered by a hairy calyptra that protects the capsule during development and influences it's shape. At maturity, the calyptra falls off to reveal a beaked operculum. [17] Like most other moss in Polytrichaceae, under the operculum P. formosom has 64 nematodontous peristome teeth that surround an epiphragm. [8]

Reproduction

Sexual reproduction

Polytrichastrum formosum is sexually dioicous, meaning the male and female reproductive structures are on separate plants. [3] P. formosum, like all members of the Polytrichaceae family, is an acrocarpous or cushion moss with reproductive structures borne at the terminus of the gametophyte stem. The perichaetial leaves surrounding the archegonia (female reproductive structure) resembles the other stem leaves besides being longer. [3] The antheridia (male reproductive structure) are at the apex of the male gametophyte in a cup-like structure formed by perigonial leaves which are modified stem leaves. [11] Sperm is produced in the antheridia via mitosis, and when mature they are released from the antheridia by raindrops splashing onto the cup. Sperm can be dispersed up to one meter from the male, and if they successfully reach an archegonia, the egg will be fertilized and grow into a diploid sporophyte. [11]

Asexual reproduction

Asexual reproduction is not extensive in P. formosum, however it occurs on a local scale by the vegetative proliferation of genets. [18]

Classification

Varieties

Taxonomy disagreement

When this species was first described by Johann Hedwig in 1801, it was classified as Polytrichum formosum. [19] Upon further analysis it was determined by Gary L. Smith in 1971 that the moss is better described by the Polytrichastrum genus. [19] Polytrichastrum can be distinguished from Polytrichum by sporangial features including multiple-angled capsules (more than 4 sided), elongated peristome teeth surrounding the ridged epiphragm, and larger spores. [6] According to several sources, Polytrichastrum formosum remains the most accurate taxonomic classification. [3] [20] However, more recent molecular data and phylogenetic analysis suggests that P. formosum should be reverted to its original genus: Polytrichum. [7] [8] Their study suggested that species in Polytrichastrum and Polytrichum are in fact distantly related, but because the Polytrichastrum genus is polyphyletic, authors suggested that some species, including P. formosum, return to the Polytrichum genus. [7] Currently, these names remain synonyms.   

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<span class="mw-page-title-main">Bryophyte</span> Terrestrial plants that lack vascular tissue

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'.

<span class="mw-page-title-main">Marchantiophyta</span> Botanical division of non-vascular land plants

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.

<span class="mw-page-title-main">Hornwort</span> Division of non-vascular land plants with horn-shaped sporophytes

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.

<i>Fissidens adianthoides</i> Species of moss

Fissidens adianthoides, the maidenhair pocketmoss, is a moss in the family Fissidentaceae. It was first collected by Hedwig in 1801.

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.

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.

<i>Polytrichum</i> Genus of mosses in the family Polytrichaceae

Polytrichum is a genus of mosses — commonly called haircap moss or hair moss — which contains approximately 70 species that have a cosmopolitan distribution. The genus Polytrichum has a number of closely related sporophytic characters. The scientific name is derived from the Ancient Greek words polys, meaning "many", and thrix, meaning "hair". This name was used in ancient times to refer to plants with fine, hairlike parts, including mosses, but this application specifically refers to the hairy calyptras found on young sporophytes. A similar naming related to hair appears in Old Norse, haddr silfjar, "hair of Sif", goddess from Norse Mythology, wife of the god Thor. There are two major sections of Polytrichum species. The first — section Polytrichum — has narrow, toothed, and relatively erect leaf margins. The other — section Juniperifolia — has broad, entire, and sharply inflexed leaf margins that enclose the lamellae on the upper leaf surface.

<i>Itatiella</i> Genus of mosses

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.

<i>Dawsonia</i> (plant) Genus of mosses

Dawsonia is a genus of acrocarpous mosses. Dawsonia, along with other members of the order Polytrichales, are taller than most mosses and have thicker leaves. Their sporophytes have conducting systems analogous to those of vascular plants. Dawsonia superba is found in New Zealand, Australia and New Guinea. D. longifolia is found in the Philippines, Indonesia, Malaysia, and Australia. There is uncertainty as to whether D. superba and D. longifolia are actually distinct species.

<i>Dawsonia superba</i> Species of moss

Dawsonia superba is a moss in the family Polytrichaceae that is found in Australia, New Guinea, Malaysia and New Zealand. D. superba is the tallest self-supporting moss in the world, reaching heights of 60 cm (24 in). It has analogous structures to those in vascular plants that support large size, including hydroid and leptoid cells to conduct water and photosynthate, and lamellae that provide gas chambers for more efficient photosynthesis. D. superba is a member of the class Polytrichopsida, although it has a sporophyte that is unique from other hair-cap mosses.

<i>Tetraphis pellucida</i> Species of moss

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.

<i>Pogonatum urnigerum</i> Species of moss

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.

<i>Climacium dendroides</i> Species of moss

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.

<i>Polytrichum strictum</i> Species of moss

Polytrichum strictum, commonly known as bog haircap moss or strict haircap, is an evergreen and perennial species of moss native to Sphagnum bogs and other moist habitats in temperate climates. It has a circumboreal distribution, and is also found in South America and Antarctica.

<i>Plagiomnium venustum</i> Species of moss

Plagiomnium venustum, also known as magnificent leafy moss, is a species of moss belonging to the family Mniaceae. It is found mainly in western North America along the coastal region. This moss can be identified from other members of the Plagiomnium genus by dark coloured stomata guide cells and the absence of sterile stems. It is most commonly found growing as a mat on a variety of substrate, but mainly on humus and moist soil.

<i>Andreaea rupestris</i> Species of moss

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.

<i>Polytrichum piliferum</i> Species of moss

Polytrichum piliferum, the bristly haircap, is an evergreen perennial species of moss in the family Polytrichaceae. The bristly haircap moss is small-sized to medium-sized and forms loose tufts with wine-reddish stems. It is an acrocarpous moss that appears bluish-green to grey. This moss grows in clumps on erect shoots and becomes a red-brown colour as it grows older. The most distinguishing feature of P. piliferum is the long, white awn at the tips of the leaves, which also give this moss its grey colour. It is the only species in its genus where the awn is completely hyaline.

Polytrichum hyperboreum is a species of moss belonging to the genus Polytrichum, commonly found throughout arctic regions of the world. Members of this dioecious species readily produces sporophytes with their sporophytic structure, consisting of a foot, seta, capsule, and a hairy calyptra, similar to other Polytrichum species. Polytrichum hyperboreum is distinguishable by certain unique features of there gametophytic structure that sets them apart from other genus members.

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.

<i>Dicranoloma billardierei</i> Non-vascular plant

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.

References

  1. ↑ "Polytrichastrum formosum". NatureServe Explorer. NatureServe. Retrieved 2022-04-04.
  2. 1 2 3 4 Webmaster, David Ratz. "Bank Haircap Moss - Montana Field Guide". fieldguide.mt.gov. Retrieved 2022-04-05.
  3. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Flora of North America North of Mexico (2007). Bryophyta: Mosses, part 1. Vol. 27. New York: Oxford University Press. p. 130. ISBN   9780195318234.
  4. ↑ Asthana, Ashish Kumar; Vinay, Sahu; Nath, Virendra (2012). "Polytrichastrum formosum(Hedw.) G.L. Smith in India". Cryptogamie, Bryologie. 33 (1): 87–90. doi:10.7872/cryb.v33.iss1.2012.087. ISSN   1290-0796. S2CID   85607035.
  5. 1 2 3 "Polytrichastrum formosum". Atlas of British & Irish bryophytes : the distribution and habitat of mosses and liverworts in Britain and Ireland. T. L. Blockeel, Sam D. S. Bosanquet, M. O. Hill, C. D. Preston, British Bryological Society. Newbury, Berkshire. 2014. p. 418. ISBN   978-1-874357-62-9. OCLC   898120353.{{cite book}}: CS1 maint: location missing publisher (link) CS1 maint: others (link)
  6. 1 2 3 Merrill, G. L. Smith (1992). "Notes on North American Polytrichaceae: Polytrichastrum". The Bryologist. 95 (3): 270–273. doi:10.2307/3243483. ISSN   0007-2745. JSTOR   3243483.
  7. 1 2 3 Bell, Neil E.; Hyvönen, Jaakko (2010a). "A phylogenetic circumscription of Polytrichastrum (Polytrichaceae): Reassessment of sporophyte morphology supports molecular phylogeny". American Journal of Botany. 97 (4): 566–578. doi:10.3732/ajb.0900161. PMID   21622419.
  8. 1 2 3 Bell, Neil; Kariyawasam, Isuru; Flores, Jorge; Hyvönen, Jaakko (2021-06-30). "The diversity of the Polytrichopsida—a review". Bryophyte Diversity and Evolution. 43 (1). doi: 10.11646/bde.43.1.8 . ISSN   2381-9685. S2CID   237385196.
  9. ↑ Glime, J. M. (2017). "Meet the Bryophytes. Chapt. 2-1". Bryophyte Ecology. Volume 1. Physiological Ecology. Michigan Technological University and the International Association of Bryologists.
  10. 1 2 3 Glime, J.M. (2017). "Water Relations: Conducting Structures. Chapt. 7-1". Bryophyte Ecology. Volume 1. Physiological Ecology. Michigan Technological University and the International Association of Bryologists.
  11. 1 2 3 Glime, J.M. (2017). "Bryophyta - Andreaeopsida, Andreaeobryopsida, Polytrichopsida. Chapt. 2-6.". Bryophyte Ecology. Volume 1. Physiological Ecology. Michigan Technological University and the International Association of Bryologists.
  12. 1 2 PRESSEL, SILVIA; LIGRONE, ROBERTO; DUCKETT, JEFFREY G. (2006). "Effects of De- and Rehydration on Food-conducting Cells in the Moss Polytrichum formosum: A Cytological Study". Annals of Botany. 98 (1): 67–76. doi:10.1093/aob/mcl092. ISSN   0305-7364. PMC   2803544 . PMID   16735407.
  13. 1 2 Proctor, Michael C. F.; Ligrone, Roberto; Duckett, Jeffrey G. (2007-01-01). "Desiccation Tolerance in the Moss Polytrichum formosum: Physiological and Fine-structural Changes during Desiccation and Recovery". Annals of Botany. 99 (1): 75–93. doi:10.1093/aob/mcl246. ISSN   0305-7364. PMC   2802982 . PMID   17158142.
  14. 1 2 Thomas, Robert J.; Ryder, Steve H.; Gardner, Mark I.; Sheetz, Jonathan P.; Nichipor, Stephen D. (1996). "Photosynthetic Function of Leaf Lamellae in Polytrichum commune". The Bryologist. 99 (1): 6–11. doi:10.2307/3244431. ISSN   0007-2745. JSTOR   3244431.
  15. ↑ Proctor, M. C. F. (2005). "Why do Polytrichaceae have lamellae?". Journal of Bryology. 27 (3): 221–229. doi:10.1179/174328205X69968. ISSN   0373-6687. S2CID   84580845.
  16. ↑ Clayton-Greene, K. A.; Collins, N. J.; Green, T. G. A.; Proctor, M. C. F. (1985-01-01). "Surface wax, structure and function in leaves of Polytrichaceae". Journal of Bryology. 13 (4): 549–562. doi:10.1179/jbr.1985.13.4.549. ISSN   0373-6687.
  17. 1 2 3 Glime, J. M. (2017). "Ecophysiology of Development: Sporophyte. Chapt. 5-9.". Bryophyte Ecology. Volume 1. Physiological Ecology. Michigan Technological University and the International Association of Bryologists.
  18. ↑ Van der Velde, M.; During, H. J.; Van de Zande, L.; Bijlsma, R. (2001-12-21). "The reproductive biology of Polytrichum formosum: clonal structure and paternity revealed by microsatellites: REPRODUCTIVE BIOLOGY OF POLYTRICHUM FORMOSUM". Molecular Ecology. 10 (10): 2423–2434. doi:10.1046/j.0962-1083.2001.01385.x. PMID   11742546. S2CID   19716812.
  19. 1 2 Smith, Gary L. (1971). "A conspectus of the genera of Polytrichaceae". Mem. New York Bot. Gard. 21 (3): 1–83. ISBN   978-0893270728.
  20. ↑ "ITIS - Report: Polytrichastrum formosum". www.itis.gov. Retrieved 2022-04-13.
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