Unfortunately, there is no accurate answer to your question, as they could be any one of a number of different varieties. You've been fortunate in obtaining good-tasting ones, as it has been my experience that these small bananas purhcased in grocery stores and small markets taste horrible. The reason is that they are picked "green" like commercial varieties to get them to the retail location, but small bananas must ripen completely on the plant to achieve maximum flavor.

For example, Ice Cream bananas (which are medium-small), taste best when harvested as they are starting to turn black.

Any banana will grow in a pot, if its other needs are being met. I have only read of rare occasions, though, with one or two varieties, that can be brought to fruit. You need a large pot, sunny location, and plenty of water and fertilizer.

I would recommend Going Bananas for purchasing high-quality plants.

-Bruce C.

Here is a link that might be useful: Going Bananas