formation: natural process that causes something to form
natural process: a process existing in or produced by nature (rather than by the intent of human beings)
welwitschia: curious plant of arid regions of southwestern Africa having a yard-high and yard-wide trunk like a turnip with a deep taproot and two large persistent woody straplike leaves growing from the base; living relic of a flora long disappeared; some may be 700-5000 years old