Welwitschia mirabilis is a perennial plant that grows up to 2 metres high. It has a taproot that is elongate, usually branching near the apex.
The woody, unbranched stem often splits into 2 lobes with an obconical shape - a conical shape but with a downwards-pointing apex. The apex growth of the stem stops at an early stage giving this peculiar and unique habit.
It has just 2 opposite, entire, simple leaves with continuous basal growth. The leaves are up to 9m long and 2m wide, tearing lengthways into strips and wearing away at the tips. The texture is leathery and the pair of leaves is parallel-veined.
It is a dioecious plant, so male and female cones are produced on separate plants:
This plant's seeds are 3.5cm long and 3cm wide, white to creamish white with persistent papery winged bracteoles.