''Polytrichum piliferum'', the bristly haircap, is an evergreen perennial species of
moss
Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta ('' sensu lato'', Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and ...
in the family
Polytrichaceae
Polytrichaceae is a common family of mosses. Members of this family tend to be larger than other mosses with a thickened central stem and a rhizome. The leaves have a midrib that bears photosynthetic lamellae on the upper surface. Species in thi ...
. 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
AWN may stand for:
* Awn Access to Justice Network in Gaza Strip, Legal Aid Network operate in Gaza Strip, Palestine
* Animation World Network, an online organization for animators
* Avant Window Navigator, a dock-like bar that tracks open wind ...
at the tips of the leaves, which also give this moss its grey colour. It is the only species in its
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...
where the awn is completely
hyaline
A hyaline substance is one with a glassy appearance. The word is derived from el, ὑάλινος, translit=hyálinos, lit=transparent, and el, ὕαλος, translit=hýalos, lit=crystal, glass, label=none.
Histopathology
Hyaline cartilage is ...
.
Common names
In
English
English usually refers to:
* English language
* English people
English may also refer to:
Peoples, culture, and language
* ''English'', an adjective for something of, from, or related to England
** English national id ...
the species goes by the common names polytrichum moss, bristly haircap, or bristly haircap moss. In
Finnish
Finnish may refer to:
* Something or someone from, or related to Finland
* Culture of Finland
* Finnish people or Finns, the primary ethnic group in Finland
* Finnish language, the national language of the Finnish people
* Finnish cuisine
See also ...
its common name is , while in
German
German(s) may refer to:
* Germany (of or related to)
**Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ger ...
it is called , , , , or .
Distribution
''Polytrichum piliferum'' has a bipolar, cosmopolitan distribution, occurring in suitable habitats on all continents including Antarctica. ''P. piliferum'' is less common than ''
Polytrichum juniperinum
''Polytrichum juniperinum'', commonly known as juniper haircap or juniper polytrichum moss, is an evergreen and perennial species of moss that is widely distributed, growing on every continent including Antarctica. and it often occurs in association with species of ''
Cladonia
''Cladonia'' is a genus of moss-like lichens in the family Cladoniaceae. They are the primary food source for reindeer/caribou. ''Cladonia'' species are of economic importance to reindeer-herders, such as the Sami in Scandinavia or the Nenets ...
''. In sandy dry grass lands the species prevents higher plants from growing.
Habitat
It is found in similar habitats to ''Polytrichum juniperinum'', however, ''P. piliferum'' prefers more open and exposed areas''.'' ''P. piliferum'' also prefers a drier environment and is able to withstand temperatures as high as 90°C to 100°C. ''P. piliferum'' can also be frequently found in areas that are acidic and low in nutrients, therefore, they can be an excellent gauge for nutrient levels.
The habitat of ''P. piliferum'' includes shallow soil over outcrops, exposed sandy soils of banks, gravel cover, and disturbed areas. Other habitats of ''P. piliferum'' includes rocks on road banks or
pastures
Pasture (from the Latin ''pastus'', past participle of ''pascere'', "to feed") is land used for grazing. Pasture lands in the narrow sense are enclosed tracts of farmland, grazed by domesticated livestock, such as horses, cattle, sheep, or ...
. It is also found in shallow and drained sand or gravel, like in ground over rocks and boulders.
Reproduction
''P. piliferum'' is
dioicous
Dioicy () is a sexual system where archegonia and antheridia are produced on separate gametophytes. It is one of the two main sexual systems in bryophytes. Both dioicous () and monoicous gametophytes produce gametes in gametangia by mitosis ra ...
, meaning that it has separate male and female plants. To sexually reproduce, this moss utilizes the splash-cup mechanism to disperse the sperm it produces from its
antheridia
An antheridium is a haploid structure or organ producing and containing male gametes (called ''antherozoids'' or sperm). The plural form is antheridia, and a structure containing one or more antheridia is called an androecium. Androecium is also t ...
. The splash-cup mechanism occurs when raindrops splash onto the antheridia, collect sperm, and are hopefully splashed onto the female plant, where the sperm can swim to the archegonia.
Gametophytic characteristics
Overall structure
''Polytrichum piliferum'' grows close to the ground (about 4 cm or less) and forms dense clusters near the tip of the shoot, forcing the stem to be somewhat bare. The stem is tall, wiry, unbranched, and a dark-red colour. The calyptra of ''P. piliferum'' is hairy and a whitish-brown color.
Leaf structure
In ''P. piliferum'', shorter leaves are located close together towards the tip of its red stems, giving the shoot a characteristic tapered shape. The leaves have a distinct white, hair-like awn at the leaf tip, in contrast to the short red-brown awns of ''P. juniperinum''. These leaves can be anywhere from 4 mm to 7 mm long, although they may be shorter in dry areas. The leaves of ''P. piliferum'' are costate and often stand erect, straight, and slightly in-curved when dry, and erect-spreading when moist.
''Polytrichum piliferum'' leaves possess parallel, longitudinal
lamellae
Lamella (plural lamellae) means a small plate or flake in Latin, and in English may refer to:
Biology
* Lamella (mycology), a papery rib beneath a mushroom cap
* Lamella (botany)
* Lamella (surface anatomy), a plate-like structure in an animal
* ...
of photosynthetic tissue on their upper surfaces, which are a unique characteristic associated with the
Polytrichopsida
Polytrichaceae is a common family of moss
Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta ('' sensu lato'', Schimp. 1879) may also refer to the parent group bryophy ...
. Another distinguishing feature of ''P. piliferum'' are the in-curved leaf blades over the photosynthetic lamellae. The topmost cells of the lamellae in ''P. piliferum'' are smooth, and under a microscope, the cross section of each lamella appears 1 cell wide and 5 to 7 cells high.
Male gametophyte
In this species, the antheridia develop from cells below the leaves. The male shoots produce a dark-red, terminal antheridia that is surrounded by a cup-shaped whorl of perigonial leaves that resembles a flower.
Sporophytic characteristics
The sporophytes of ''P. piliferum'' are common and usually reach maturity during the summer. The sporangia are cube-like and inclined, but become more horizontal when mature. They are borne on the red-brown seta that is approximately 1 cm to 3 cm in height.
Conservation status
''P. piliferum'' is ranked globally as secure (G5) as of 1/26/2015, meaning that this species is at a very low risk of becoming globally extinct due to an abundant population. In Canada, ''Polytrichum pilifeurm'' is ranked as secure (N5), meaning that this species has a very low risk of becoming extinct in Canada due to a high presence in an extensive habitat.