The fruit of the potato with seeds inside.

It is possible to graft a tomato and potato together. So theoretically you could have a potato rootstock with a tomato top. I am not sure what kind of harvest you could get from doing this.

Some interesting potato information:

A potato is really a stem that's modified for storage; the eyes are really buds.

Potatoes are grown in all 50 states.

Americans eat an average of 143 pounds of potatoes per person per year.

As the most important vegetatively propagated food crop in the world, potatoes rank 4th after rice, wheat and corn in overall importance, world-wide. Potatoes produce more food per acre than any other crop.

Speaking of seed, in mid-summer, sharp-eyed gardeners may notice green marble size fruits amid the foliage of their potatoes. Each of these fruits yield approximately 300 true seeds. Seeds like these are used by potato breeders to find potential new cultivars as each one is geneticially distinct, like children in a family. Just for fun, clean and save some of the seeds and plant them inside in mid-March. (You need not worry about disease transmission as you would with "seed potatoes", as very few diseases are seed transmitted.) After frost danger has passed, transplant the potato seedlings into the garden and wait. See what you get! Notice how variable the potatoes are from plant to plant.

From http://www.extension.umn.edu/yardandgarden/YGLNews/YGLN-May0100.html

More info - http://www.extension.umn.edu/projects/yardandgarden/ygbriefs/H212potatoes.html

Well, I know they aren't grafted - Clayton started these from purchased tubers at the nursery. I've never seen them on potato plants before. Maybe we will have to try the seed next year. Thanks!

Lynn

Sorry...I didn't mean to imply your plants were grafted. It was how one would grow a tomato and potato on one plant.