Because of the length of its leaves this male Welwitschia was estimated to be about 100 years old. Seedlings need substantial rainfall to take root, a rare event which does not occur most years in this desert. Established plants obtain practically all their water from fog. Fog forms during the night when hot desert air meets the cold Benguela Current. This fog rolls inland and typically vanishes by 10 am. Fog condenses on the leaves where the water is taken in by stomata and drips down to the roots.