Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         "crystal-kingdom"
           chemical substances
             chemical compounds
               Class hydrocarbons [CxHy] - compounds consisting of carbon and hydrogen only
                 Class olefins
                   Class alkenes [CnH2n] - unsaturated acyclic hydrocarbons having one double bond
                     3-methyl-1-butene [C5H10; CH2=CHCH(CH3)CH3]