evening: the early part of night (from dinner until bedtime) spent in a special way
measure: how much there is or how many there are of something that you can quantify
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