If we are going to include fats and vegetable oils in this discussion there is some interesting reading here-
http://www.whatislife.com/reader2/M...fattyacids.html
Biological oils and lipids are widely encountered in metabolism; but the heavier alkanes, alkenes, and propanol-type compounds are less frequently used in biological systems.
Some turpentine and resin producing trees can probably produce spirit which could be used as motor fuel...