Photo by Jörg Hempel licensed under CC BY-SA 3.0 de
Meet the gas plant, Dictamnus albus. This lovely herbaceous species is native to southern Europe, north Africa, and Asia. The gas plant is a member of the citrus family, Rutaceae, and like many members of this group, it has very showy blossoms. Its affiliation with the citrus fruits on your counter isn't the only interesting thing about this species. As the common name might suggest, this plant does something quite strange.
During the heat of summer, parts of the gas plant exude an oily substance that smells much like the fruits of its cousin, the lemon. These oils have been known to cause contact dermatitis not unlike the sap of giant hogweed. However, this is not the strangest aspect of the gas plants oily nature. One of the properties of these oils is that they are highly volatile. So volatile in fact that they can ignite.
Another common name for this species is burning bush (though not the one of biblical lore). If air temperatures get high enough or if someone takes a match to this plant on a hot day, the oils covering its tissues will ignite in a flash. The oils burn off so quickly that it is of no consequence to the plant. It goes on growing like nothing ever happened. If you're like me then you have one burning question after reading this - why?!
Despite how incredible this phenomenon may seem, it doesn't appear that too many people have looked into its function. Research has identified a highly flammable organic compound within the oils called isoprene. In plants, isoprenes are thought to protect against heat stress. This is bolstered by the fact that the gas plant produces these compounds during the heat of summer.
Another possibility is that spontaneous ignition of these compounds could create small wildfires that clear the surrounding area of competition. I have not seen any evidence suggesting this. Yet another possibility is that this is simply an unrelated side effect of oil production. Since the plant is not hurt by the quick burst of flames, it simply hasn't had any reason to evolve a less flammable alternative. Evolution is funny like that.
Still don't believe what you are reading? Check out this video: