Description
Leaves
''Plagiomnium cuspidatum'' has sharp-toothed leaf margins, as its common names suggest, and can be identified from other members of the ''Plagiomnium'' genus by their leaves which measure to about 2.5–3.5 mm in length and have a tip that is tapered more gradually than other ''Plagiomnium'' species, a leaf base that runs all the way down onto the stem, and leaf cells that are elongated and clearly not arranged in diagonal rows. ''P. cuspidatum'' is often characterized as a small moss with shoots ranging from 1.5-4 cm tall and leaves roughly around 3 mm long. Leaves of ''P. cuspidatum'' gradually taper towards the tip, more so than other species in the genus. Leaf margins are sharply toothed and are absent in the lower half of the leaves while the midrib is obvious. Leaves are arranged in pseudo whorls- where the arrangement of leaves appear to originate at the same level but do not. Using a x20 hand lens, the small cells can be seen to not be in diagonal rows and no longer than wide. The non-fertile stems can be one of two descriptions: erect or curved. When aggregated together, the plant forms a green cushion-like structure. When dry, the leaves darken and begin to curl.Reproductive structures
''Plagiomnium cuspidatum'' do not reproduce asexually but are dioicous – having antheridia and archegonia on separate plants – and synoicous- having archegonia and antheridia on the same plant. From the foot of the plant, there can be multiple seta that raises the capsules above the plant. Capsules are frequent have a conical lid. Spores range from 18-40μm and are numerous inside the capsule.Distribution
''Plagiomnium cuspidatum'' originated in North America, but can now also be found throughout Middle America, Africa, Northern and Southern Asia (excluding China), and Europe. It is widely distributed throughout North America and Europe, but is less commonly found in Africa and Eastern Asia. Throughout North America, it can be predominantly found in the warmer, humid areas of the continent, though it can still be found and survive in more cooler climates as well. ''Plagiomnium cuspidatum'' is known to be able to use artificial light to grow in places which are otherwise devoid of natural light, such as Crystal Cave in Wisconsin.Ecology
Within North America and Europe, ''P. cuspidatum'' is often found growing along the base of trees, stumps, coarse woody debris, and rocks in base-rich habitats such as: wet meadows, forested rich peatlands, wet forests, fire-dependent woodlands, mesic hardwood forests, and cliff/talus at low to moderate elevations. The moss is often used by songbirds to make the inner lining of their nest and by four-toed salamanders (''Hemidactylium scutatum'') when nesting to prevent movement of their eggs. Located at the bottom of the mosses, the rhizomes are used by the salamanders to attach their eggs to, which aids in stabilization.Uses
Cultivation
It can be used as a planting medium in bioactive terrariums, aquariums, and paludariums too due to its anti-microbial and antifungal properties. Its ability to retain high humidity levels and grow in mats or carpets, which provides great cover for the tank's " clean-up crew", also make it perfect for the hobby.Medicinal
In many bryophytes, there have been antibacterial, antiviral, and antioxidant properties associated with certain species. ''P. cuspidatum'' is able to produce substances that can inhibit bacteria and fungi. But due to these substances being unstable, they have not been able to be used in the medical field but have garnered some attention for its potential use. The instability of the substance stems from the substance being produced while the moss is under stress and a variety of species produce a variety of substances. It has been seen that ''P. cuspidatum'' showes resistance to methicillin-resistant ''References
{{Taxonbar, from=Q292398 Mniaceae