Introduction: Hundreds of millions of years ago, live moved from the oceans to land. One of the first colonizers were microscopic critters that were able to use the Sun to make energy for themselves. Overtime, these organisms became very simple plants called bryophytes - the liverworts, hornworts, and mosses.

The reason these plants are called nonvascular is because they lack the organized tissues found in higher plants, the xylem and phloem. As a result, these plants need to live in areas that are constantly wet. They also cannot grow very tall because they lack stems to transport water.

Most people have heard that moss only grows on the north side of rocks and trees, ever helping the person lost in the forest. This statement is mostly true because the north side of the tree never receives direct sunlight. As a result, it is cooler than the other three sides and also stays wetter. Mosses thrive in this type of environment.

Nonvascular plants undergo photosynthesis just as any plant would, but they are much more sensitive to changes in light.

Nonvascular plants use their watery environment for reproduction. Since they live in areas that are usually very moist, the sperm from one plant has no trouble swimming to another plant to join with the egg.

Directions for this Lesson: Answer the practice questions and then watch the video to learn more about nonvascular plants.