“Cheerios are donut seeds”

Cheerios cereal has been called “donut seeds” on several images. “Polish Donut Seeds” (Cheerios) were sold in 1979. “There was enough time to sell Cheerios as donut seeds to the crowd” was printed in a 1980 newspaper.
 
   
Wikipedia: Cheerios
Cheerios is an American brand of cereal manufactured by General Mills, consisting of pulverized oats in the shape of a solid torus. In some countries, including the United Kingdom, Cheerios is marketed by Cereal Partners under the Nestlé brand; in Australia and New Zealand, Cheerios is sold as an Uncle Tobys product. It was first manufactured in 1941 and was originally called CheeriOats.
     
Google Books
The Newest, Most Unique Ways People Are Making Money
By Chase Revel, John Hiatt, et al.
Santa Monica, CA: Baronbrook Pub. Co
1979
Pg. 37:
“Polish Donut Seeds” have recently been introduced to the U.S. market and promise to be as successful as Polish pistols (with the barrel pointed toward the shooter), Polish coffee mugs (with the handle inside), and other inventions along those lines.
 
The tiny seeds are actually ordinary Cheerios which come packaged in an envelope with complete planting and care instructions, including the important fact that they must be planted “with the left side up,” and cultivated at 3 a.m. daily.
 
14 February 1980, State-Times (Baton Rouge, LA), “LSU dillied and Auburn dallied” by Sam King, pg. 2-C, col. 1:
There was enough time to sell Cheerios as donut seeds to the crowd.
 
1 March 1981, Newsday (Long Island, NY), “Smiles,” Kidsday, pg. N9, col. 3:
What did the man say when his wife poured him a bowl of Cheerios?
“Oh, donut seeds!”
—Lori Gulotta, Deer Park
 
Google Books
Rednecks
By Larry Wilde
New York, NY: Bantam Books
1984
Pg. 3:
Did you hear about the redneck who planted Cheerios in his back yard? He thought they were donut seeds.
 
Google Books
More Ole & Lena Jokes
By E. C. Stangland
Sioux Falls, SD: Norse Press
1987
Pg. 48:
And not to forget the Norwegian donut seeds which look suspiciously like Cheerios.
   
Google Books
Clean Jokes for Kids
Uhrichsville, OH: Barbour Publishing
1998
Pg. 58:
Cheerios: donut seeds.
   
Google Books
The Jumbo Book of Blonde Jokes
By Ed Sullivan
Bramhall, Cheshire: Cool Publications
2004
Pg. 9:
Q: What did the blonde say when she looked into a box of Cheerios?
A: “Oh look! Donut seeds!”
 
Twitter
insults‏
@insults_1747174
You’re mother is so fat and stupid,she planted Cheerios in the ground , thinking they were donut seeds!
1:35 AM - 22 Oct 2007
 
Twitter
enderFP‏
@enderFP
i thought cheerios were donut seeds
4:22 PM - 2 Apr 2008
 
Twitter
enderFP‏
@enderFP
cheerios are donut seeds.  plant them.  you’ll get a donut tree.
7:53 AM - 8 Apr 2008