Those rather old and dried out mystery seeds from last week will hopefully grow up to be zinnias, which is the common name for about 20 different species in the genus Zinnia.
The flowers are pretty familiar garden plants that love to grow in warm weather.
This photograph of a lovely red zinnia by Peter Griffin is from PublicDomainPictures.
Looking around for zinnia flower pictures, I also found a photograph of the seeds taken under a microscope that I just had to share.
This photograph is by John Alan Elson at Wikimedia.
You can clearly see the triangular or arrowhead shape of the zinnia seeds.
Are you going to be growing any zinnias in your garden this summer?