08 December 2006
Vol 314, Issue 5805

About The Cover

Cover image expansion

COVER The grass Sorghastrum nutans, one of a dozen plant species that dominate native North American prairies. Biofuels produced from diverse mixtures of prairie plants can provide greater energy yields and environmental benefits than food-based biofuels such as corn ethanol and soybean biodiesel. See page 1598. Photo: Jason Hill