transpiration

American  

[tran-spuh-rey-shuhn] / ˌtræn spəˈreɪ ʃən /

noun

1. an action or instance of transpiring.

2. Botany. the passage of water through a plant from the roots through the vascular system to the atmosphere.

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transpiration Scientific  

/ trăn′spə-rā′shən /

1. The process of giving off vapor containing water and waste products, especially through the stomata on leaves or the pores of the skin.

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Closer Look

Plants need much more water than animals do. But why? Plants use water not only to carry nutrients throughout their tissues, but also to exchange gases with the air in the process known as transpiration. Air, which contains the carbon dioxide that plant cells need for photosynthesis, enters the plant mainly through the stomata (tiny holes under its leaves). The air travels through tiny spaces in the leaf tissue to the cells that conduct photosynthesis. These cells are coated with a thin layer of water. The cell walls do not permit gases to pass through them, but the carbon dioxide can move across the cell walls by dissolving in the water on their surface. The cells remove the carbon dioxide from the water and use the same water to carry out oxygen, the main waste product of photosynthesis. All this mixing of water and air in transpiration, though, has one drawback: more than 90 percent of the water that a plant's roots suck up is lost by evaporation through the stomata. This is why a plant always needs water and why plants that live in dry climates, such as cacti, have reduced leaf surfaces from which less water can escape.

Etymology

Origin of transpiration

1545–55; trans- + Latin spīrātiōn-, stem of spīrātiō breathing ( spīrāt ( us ), past participle of spīrāre to breathe + -iōn- -ion ); perhaps directly < French or New Latin

Compare meaning

How does transpiration compare to similar and commonly confused words? Explore the most common comparisons:

• transpiration vs. evaporation

Explanation

Plants breathe through their stomata, little openings that allow transpiration, which is the outward passage of water vapor along with carbon dioxide. This vapor then evaporates into the air as part of the process of photosynthesis. We can see the history of the word transpiration when we break it down into trans, a Latin noun which means "across," and spiration, which comes from the Latin verb spīrāre, meaning "to breathe." The tion suffix adds the meaning "the act of," so we can see transpiration is, literally, "the act of breathing across," which clearly identifies vapor emission from plant leaves. Transpiration is vital to the earth’s ecology, and is being reduced by our decimation of the forests.

Example Sentences

Transpiration causes water to return to the leaves through the xylem vessels.

From Textbooks • Jun. 9, 2022

Transpiration is the loss of water from the plant through evaporation at the leaf surface.

From Textbooks • Jun. 9, 2022

Transpiration and in turn, photosynthesis would not occur which is necessary to maintain a continuous flow of water upwards from the roots to the leaves.

From Textbooks • Jun. 9, 2022

Transpiration is the loss of water through leaves, which may be replaced by water drawn into the leaf through xylem in the vascular tissue.

From Textbooks • Jan. 1, 2018

Transpiration, the giving off of water from plants.

From The First Book of Farming by Goodrich, Charles Landon

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