Welwitschia mirabilis is one of the most curious and bizarre plants of the plant kingdom; in the course of its very long lifetime (by some accounts the oldest plants may live to about 2000 years), it will only produce two mature leaves, which lengthen seasonally as the plant grows. In established plants in habitat, the leaves will eventually become quite long (sometimes in excess of 20 feet), becoming split and tattered towards their ends. Eventually, the leaf tips die back and break away as the plant grows, limiting their ultimate length. The leaves are thick and quite tough, some authorities report that they are leathery, but in the few mature plants which I have examined, the leaves were much tougher, more like cardboard or wood, (very similar to the leaves of the "Cardboard Palm", but even tougher).
