Survival 101: How to Collect Water From Dry Plant Leaves

Last month we watched pond weed produce oxygen from just water and sunlight. But we also know that land plants (a.k.a. vascular plants) produce oxygen too. This can be observed by simply placing a living leaf (i.e. not dried out) under water. After a while, small gas bubbles will be seen on the surface of the leaf. This is the oxygen that the leaf is producing. But that's not all that vascular plants produce from their pores. Vascular plants also produce water through a process known as transpiration. 

Transpiration is the process by which vascular plants take in and release water as needed. Water moves from the roots of the plant up through the plants tissues. This is why a white flower, such as a carnation, changes color when its cut stem is placed in a container of water with food coloring added. As the flower draws the water up into its tissues, the food coloring is drawn into the tissues as well.

When the pores on the leaves of a vascular plants open to let carbon dioxide in, they also release excess water. And this plant-purified water can be easily collected. All you need to do is find a living plant (preferably a tree with leaves) and without damaging the plant, place several leaves in a water-tight bag. Be sure to include some air in the bag. Seal the bag around the branch using twine, rubber bands, or twist-tie.

Over time, you will notice that the bag now seems to contain liquid. This liquid is the water that the plant's leaves have produced during transpiration.

Is this the best way to purify water? No, probably not. You would need a lot of time, a lot of bags, and you would probably never be able to collect enough to sustain yourself for a long period of time (health authorities recommend the average human drink 2 liters of water per day). Plus, it would depend on how clean the leaves were to begin with, and whether the plant itself was toxic. Still, it does prove that plants are an important part of Earth's water cycle.

Congratulations super-scientist! You can now collect water using the power of plants!