Potatoes: Please Explain.

Once the tuber has been planted, the stem grows up, and is it from the stem underground that the new tubers grow?

What happens to the original tuber?

If the tubers all produce "eyes" or buds, why do these not all develop into new stems? If they do, can a tuber ne "connected to" more than one stem - ie the original one it grew from, and the new stem it sends up?

When I have seen tubers they always have plenty of "eyes," but in pictures of underground potatoes, the tubers are simply growing from a single line from the original plant. They have no or few "eyes." In this picture, http://comps.fotosearch.com/comp/IGS/IGS653/potato-tubers-plant_~IS411-090.jpg the individual potatoes have no eyes. How can they be said to produce more plants? If you see a clump of potato plants, does that mean each stem originates from a single tuber?

Where are the roots?

 

The original tuber rots away.

 

I'm not sure, but in practice the tuber sends up more than one shoot, sometimes its suggested that you should remove some of the shoots of chitted seed to about three shoots.

Either way, like any plant it seems to put most energy into one main shoot and a couple of lesser shoots, all capable of growing spuds.

Not sure if its true, but its usually said that the more stems you have on one plant the smaller the spuds.

The new tubers grow from the stems produced and as Palustris says the old seed tuber usually rots.

The new tubers produced are resting tubers and will not produce stems until the following season.