Well, dandelions produce rubber, and Russian dandelions produce the best.
With the help of precision breeding, the researchers were quickly able to double the amount of natural rubber in the Russian dandelion. This was achieved without genetic modification; instead, Dirk Prüfer and Christian Schulze Gronover analyzed the dandelion's genome and identified suitable DNA markers. These genetic tools could tell already in a very early stage of plant development if a given plant will possess an efficient rubber production.
Extraction of natural rubber from the plant was another challenge. To this end, the scientists developed an eco-friendly technique whereby only the roots are pulverized because the leaves contain very little rubber. At the end of the process, water is used to separate the resource from the other substances.
Read more at: http://phys.org/news/2015-06-natural-ru ... s.html#jCp