One of the most common and used plants are soybeans to aid the process of biodiesel fuel. What happens is the combining of oils from the soybeans chemically, with alcohol. Flax, mustard and sunflower seeds are other sources. Because the fuel is from a natural produce, its only fitting.
In fact animal fats and algae are also some sources for the manufacturing of materials. Fuel is a great way for companies to try and save the planet by becoming an eco-friendly company. It really does help a companys reputation when they are actively seen to aid in saving the environment.
Also as Biodiesel fuel can be produced from recycled waste it means that companies can use the waster for material to make the fuel. Its a cheaper way of running things. A respected burger chain restaurant uses old cooking oil and converts into biodiesel fuel for their trucks to transport materials such as cooking oil. So its a cycle. Imagine if every business did this, the world would be saved in no time!
Biodiesel is one of the ways forward in terms of saving the environment. Its not as clean as electric energy but its cheaper and a more realistic alternative.