Credit: José Luis Benito Alonso

Thirsty plants can extract water from the crystalline structure of gypsum, a rock-forming mineral found in soil on Earth and Mars.

Some plants grow on gypsum outcrops and remain active even during dry summer months, despite having shallow roots that cannot reach the water table. Sara Palacio of the Pyrenean Institute of Ecology in Jaca, Spain, and her colleagues compared the isotopic composition of sap from one such plant, called Helianthemum squamatum (pictured), with gypsum crystallization water and water found free in the soil. The team found that up to 90% of the plant's summer water supply came from gypsum.

The study has implications for the search for life in extreme environments on this planet and others.

Nature Commun 5, 4660 (2014)