Introduction to Moss
Moss is the simplest plant to have evolved and adapted to live on land. The plant division is called Bryophyta, there are around 12,000 different species of bryophytes. Bryophytes used to include other plants like liverworts and hornworts but were eventually fazed out. Here we will discuss how mosses adapted to life on land.
Adaptation 1: Moss develops Rhizoids which are analogous to roots
The little roots coming off the plant are actually called Rhizoids. They help the plant by absorbing water and anchor the plant to a substrate. The main difference between Rhizoids and Roots are that Rhizoids are very small and don't grow that much. Rhizoids can also be unicellular while roots are always multicellular with vascular tissue, xylem and phloem.
Adaptation 2: Microphylls are analogous to leaves
Moss does not have leaves. They instead have less advanced structures called microphylls which still serve the same purpose as leaves. Each little "leaf" has just one unbranched vein in it. Megaphylls, common leaves found on other plants, have larger veins that branch off into smaller ones on the leaf.
Adaptation 3: Cuticle
The cuticle is a waxy coating or film on a plants microphylls and megaphylls. This neat adaptation helps the plants retain water by preventing it from evaporating away from the plant.
Adaptation 4: Stomata
Stomata are little pores that open and close to release oxygen and take in carbon dioxide. Due to plants having developed a cuticle, they need a way for carbon dioxide to cycle/flow in and oxygen to flow out , thus plants developed the stomata for the function of cycling.
Adaptation 5: Gametangia
-Moss Sporophyte
The final step in evolution for bryophytes was the development of the Gametangia which is basically a receptacle for gametes.
5 moss species from the Pacific Northwest
Oregon Beaked Moss(Kindbergia oregona) Picture 3
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Wet Rock Moss (Dichodontium pellucidum) Picture 1 |
Fragile Fork Moss (Dicranum tauricum) Picture 2 |
Plagiomnium Moss
(Plagiomnium venustum) Picture 4
Tree Moss(Isothecium Myosuroides) Picture 5
More facts about moss
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