An international consortium announced this week that it has finished the first genome sequence of a higher plant. For plant biologists, the eagerly awaited genome of this small weed, Arabidopsis thaliana, offers a window into the genetic makeup of all plants, including key crops. And it's a clear window indeed, as the six international sequencing teams on three continents have produced a genome sequence that is more complete than that of any multicellular organism which has been published to date. Through this window, they are seeing for the first time that plants may be much more complex than many biologists have imagined.