The spaceship lands. He steps out. He points it around. It says ‘friendly–unfriendly—edible–poisonous—safe– dangerous—living–inanimate’. On the next sweep it says ‘''Quercus oleoides—Homo sapiens—Spondias mombin—Solanum nigrum—Crotalus durissus—Morpho peleides''— serpentine’. This has been in my head since reading science fiction in ninth grade half a century ago.