Anyone familiar with Ernst Haeckel's species rich moss illustration knows that mosses can be quite exquisite.
Although they're generally small plants (usually up to about 10cm with some aquatic species reaching up to a meter in length maximum) they're hugely important in most ecosystems and are capable of surviving under extreme environmental conditions that not many plants can tolerate.
These small wonderful organisms are widely distributed and grow in variable conditions from aquatic to tropical and alpine environments.
Mosses are much unlike flowering plants. They have stems with leaves but no true roots. Instead of roots they have thin root-like growths called rhizoids that serve to anchor them into a substrate.
They're poikilohydric organisms, meaning they don't maintain a constant state of hydration. Mosses are adapted to dry out and rehydrate as soon as water is available.
If you've ever collected dry moss and put it in a bowl of water you can clearly observe how it takes up water, often within seconds. Water and minerals are primarily absorbed directly through the leaves. Although mosses don't contain a vascular system they can still guide water to where it is needed through capillary action.
Basic Moss Physiology
Mosses rely on damp conditions for sexual reproduction because the sperm moves through water to reach the egg. The female sex organ is called the archegonium and the male sex organ is known as the antheridium.
Once the egg is fertilised sporophyte grows and matures. The sporangium is supported by the seta/stalk which supplies it with nutrients while it matures. Once mature, the spores are dispersed and germinate where conditions are right. Spores are unicellular rather than multicellular like seeds but they both serve the purpose of reproduction.
what you need to identify mosses:
• A x10 to x20 handlens
• A guide e.g. Mosses and Liverworts of Britain and Ireland
• Understanding of moss physiology
Mosses can look rather similar to one another so identifying them is difficult. The key to identification of any organism is observation and patience. Now that you know the basic structure of a moss you can have a go at identifying some in your neighbourhood. I promise you won't have to look far, because mosses are extremely wide spread. If your based in Europe you can make use of the printable moss identification booklet included at the bottom of the page. It has very clear illustrations that will help to identify the moss you find. However consider that it only features a few mosses so you might not find what you're looking for.
Happy moss identification!