Grass by Sheri S. Tepper

What could be more innocuous than grass? Or more idyllic than a world covered with a wind-whipped ocean of verdant plains? But the planet Grass conceals horrifying secrets within its endless pastures. And as an incurable plague attacks all inhabited planets but this one, the prairie-like Grass begins to reveal these secrets - and nothing will ever be the same again ... Considered to be among one of Sheri S.