Scientists from the University of Haifa has discovered that a rare desert plant “waters itself,” enabling it to receive 16 times the amount of rainwater that falls on it each year.
Professors Simcha Lev-Yadun, Gidi Ne’eman and Gadi Katzir investigated the desert rhubarb, Rheum Palaestinum, during a trip with students to the Negev. Unlike most desert plants, it has broad leaves with many grooves that channel rainwater straight to its roots.
Whereas only about 75 millimeters of rain fall on the rhubarb’s habitat yearly, the plant's unique irrigation system provides it with as much water as if 425 millimeters were reaching its roots. And whereas rain generally only reaches about one centimeter into the ground, the rhubarb’s irrigation system takes the water ten centimeters under the earth to the deepest part of its roots.
The scientists explained that the series of grooves and notches on each leaf’s surface are a miniature imitation of the topography of the surrounding desert mountains and wadis, maximizing the amount of water flowing to the plant’s roots. In addition, they pointed out that the leaves have a wax covering which helps the water flow.
“We know of no other desert plant in the world that does this,” the researchers said. Their discoveries were published recently in the journal Naturwissenshcaften.