Our mystery seeds from last week were indeed chestnuts, Castanea sp.
These chestnuts were purchased at the grocery store, so they are most likely what are called sweet, Spanish or European chestnut, Castanea satvia.
(Illustration from the public domain at Wikimedia - Castanea satvia is a newer name )
The story of the American chestnut, Castanea dentata, is of course a sad one. The majestic trees were once a common sight throughout Eastern North America, but they virtually disappeared due to the chestnut blight.
The good news is that scientists are making some excellent progress developing chestnut blight resistant trees. I'm most familiar with what is going on at my Alma Mater, SUNY College of Environmental Science and Forestry's Research and Restoration project.
In this TED video, ESF's Dr. William A. Powell explains a little of the history and what is being done to try to bring back the American Chestnut, If you are interested in trees, it is well worth the 15 minutes viewing time.
Check the comments on YuTube if you are interested in what others think of this program.
For more information, you also might check the American Chestnut Foundation.
Have you ever seen an American chestnut growing?