High oil prices and concern about global warming revived global interest in alternative energy sources to replace fossil fuels, but almost every promising solution has triggered its own set of environmental and price controversies.

Take corn ethanol, for example: critics say that it's not very energy-efficient, and the increasing use of corn to produce fuel has made the food staple more expensive. Or biodiesel derived from palm oil, which is heavily criticized for fostering rapid deforestation in India and Malaysia -- aggravating, instead of helping solve the greenhouse gas problem. A recent story about Imperium Renewables' biodiesel plant in Grays Harbor -- the biggest such facility in the U.S. -- generated substantial response of readers either lauding the virtues of the fuel or decrying its environmental impact.

These debates have made many pin their hopes on jathrofa, a rugged little plant that's is showcased in a Wall Street Journal cover story today. The shrub can grow practically anywhere, is inedible (so it doesn't compete with food) and its seeds contain a palm oil-like liquid that can be turned into biodiesel. Jathrofa-based biodiesel's production cost is also lower than other alternative fuels, the story says.

The crop is still in the very early stages of its career as a fuel feedstock, but some 30 million hectares of jatropha are under development worldwide, reporter Patrick Barta says in a video posted at the WSJ's website.