An official website of the United States government
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
 Image Number D479-1 |
Microbiologist Jerry Sims holds a culture of giant ragweed (Ambrosia trifida) seeds embedded in agar, some overgrown with soil microorganisms. Sims is investigating how and why some weed seeds escape decay by these organisms.
Photo by Peggy Greb.
