Mosses

Mosses growing on a tree and on my lawn

What characteristics unify mosses? 

Mosses are part of the phylum Bryophyta. Mosses need to live in a wet environment to survive. They thrive and grow most abundantly in  bogs, swamps, moist woods, and near streams. Mosses vary in appearance, but most are less than a few centimetres tall. They lack the water conducting tubes that are found in more complex plants, true roots, stems or leaves. 

This is an illustration of the typical moss plant

This diagram explains how mosses reproduce via alteration of generations. Alternation of spore producing generation (sporophyte 2n) with gamete producing generation (gametophyte n). 

Photo from: http://scitec.uwichill.edu.bb/bcs/bl14apl/bryo1.htm

What features do mosses have that have enabled adaptation to a land environment?

Mosses have several features that have enabled them to adapt to land environments. They have developed a multicellular plant body. Special structures like rhizoids developed which absorb water and are used for anchorage. They also have photosynthetic tissue that help in the absorption of carbon dioxide without losing much water from exposure to light.