Moss

Overview

[8]

Moss is a group of plants that belong to the group Bryophyta. They are typically 0.2–10 cm (0.1–3.9 in) tall, and have a waxy cuticle to prevent water loss. Moss can be found in any wet envrinment because they rely heavily on water to grow, and reproduce. Rainforests and wetlands are great environments to find moss. They also love the shade, which is why they are found under rocks and at the forest floor. Moss is extremely resilient and can tolerant many toxins, which is why it can also be found in urban areas, growing in cracks in the sidewalk or on the sides of buildings. Moss offers a food source and habitat for invertebrates, it filters toxins out of water, and protects the ground from erosion.

Structure

Structure of Moss [2]

Moss lacks vascular tissue, which is what other plants use to transport water and nutrients throughout them. Because they lack this tissue, they do not have flowers, roots, or stems. Instead, it has rhizoids, which act like roots holding the cluster in place. Without vascular tissue, water is transported from cell to cell by diffusion. The capsules are the sex organs, and where the spores come out. The stemlike structure supports the leaflike structures, called phyllids. These are the part of the plant that carry out photosynthesis.

Life Cycle

Moss have two parts to their life cycle. The first part, called sporophyte, is the stage where spores are produced. The spores are carried by wind to populate other areas. The second stage, called gametophyte, is after the spores found a place to grow. They develop male and female sex organs, which allow for reproduction. The male sex organ is an umbrella shaped antheridial head, which contains sperm. The female sex organ is called an archegonial head, which is looks like little fingers, and each finger contains one egg. When it rains, the water splashes the sperm out of the antheridial head, and they swim to the eggs through water droplets. Water is essential in the reproduction of moss, which is why it can only grow in moist environments.

Environmental Role

Mosses play an important part in stabilizing soil, and reducing erosion. Their rhiziods grip the ground and can hold on to clay, gravel, and sandy substrates. Moss is very tough, and can withstand many toxins and heavy metals that might be in rainwater. Undesirable elements like mercury, iron, and lead are filtered our through moss, which means that moss can be used to restore land that has been abandoned due to bad soil conditions. In addition to heavy metals, moss can filter other pollutants picked up in run off, like excess sediment and salt used on roadways. Moss has the ability to retain a lot of water, which means it creates humid environments, where other plants can flourish more easily. It also aids in the decomposition of organic material, such as fallen trees.

In the garden, moss can be used as a natural pesticide. Moss has internal anti-hebivory compounds, which cause it to taste bad, especially to deer.

References

[1] Asher, Beth. “Describe the Structure of a Moss Plant.” Hunker, [[1]].

[2] “Bryophytes.” Prentice Hall Biology, [[2]].

[3] Lizarazo, Andres. “Moss to Ferns.” SlideShare, 23 Apr. 2014, [[3]].

[4] Martin, Annie. “5 Environmental Benefits of Moss Gardening.” Timber Press, 9 Sept. 2015, [[4]].

[5] McLintock, A. H. “Polytrichum, Showing Both Male and Female Gametophytes as Separate Plants.” An Encylcopedia of New Zealand, 1966, teara.govt.nz/en/1966/24024/polytrichum-showing-both-male-and-

       female-gametophytes-as-separate-plants.

[6] “Moss.” Basic Biology, 23 May 2015, [[5]].

[7] “Moss Facts.” Soft Schools, [[6]].

[8] “Moss.” Wikipedia, 21 Mar. 2019, [[7]].

[9] Stein Carter, J. “Primitive Plants: Mosses, Ferns, and Allies.” Biology Clermont, 11 July 2017, [[8]].