Gift to the Thirsty was a rare native root plant on Arrakis which grew above the 2500-meter level in the northern temperate zone. It owed its name to its high water content: a tuber two meters long yielded half a liter of water, which was many times over the moisture that could be obtained from an equivalent weight in other vegetation. The water, the Fremen assumed, was not being drawn out of the atmosphere; somehow, the tubers were responsible for pulling it in.