The USA-NPN website will be temporarily unavailable for scheduled maintenance beginning late Sunday, July 26 through early Monday, July 27 (EDT). Thank you for your patience and understanding.
We are undertaking a major revision of our Nature's Notebook data collection app to make it easier and more fun to track plant and animal seasonal activity!
The outer whorl of the flower's perianth and the collective terminology for all of the sepals of a flower; typically green and which often protect the flower bud