Welwitschia mirabilis

Welwitschia mirabilis  is the only member in the family Welwitschiaceae and is one of the more bizarre plants on the planet.  It was named after Friedrich Welwitsch, an Austrian naturalist who explored Africa in the 1800's.  Welwitschia is the most incredible plant that he encountered.  It is native to a strip of land about 50 miles wide and over 500 miles in length along the coast of the Namib Desert.
In habitat, these plants get less than one inch of rainfall per year.  But because of a cold, coastal ocean current, this area also gets a regular fog, adding almost another two inches of precipitation.  As a result, these plants in nature are slow growing and can live to be 2000 years old!!  They are coning plants with male and female cones on separate plants. (Female cones below; male cones middle right.)  They produce only two true leaves in their lifetime and those leaves continually grow from the base, all the while, dying back and drying off at the tips. 

In cultivation, Welwitschia mirabilis used to be considered difficult, so they were mostly underwatered to prevent rot and usually died from underwatering.  These are not succulent plants, so should not be allowed to dry completely at any time.  During the warm season, if under very bright light (full sun in Tucson is just a little too much--famous understatement!) they can be watered copiously, if potted in a well drained cactus type mix.  It also used to be thought that they must have a deep pot to thrive, but it is now known that they will live quite nicely in a standard depth pot.  Like any plant, they will slow their growth when pot bound.  The seedlings at right are in a 2" X 10" tube, but will be potted into a standard 5-gallon container, about 10" X 14" for the next many years.