Toni,it will have to get some size on it before you see the swollen base; I've seen pictures of plants with that swollen base and they do look like bonsai. It is a form of B. dregei from South Africa, it produces three forms and yours is one of the better known. They can be mildew prone so make sure you have good aeration where you grow it. If it is spindly give it good light, if you pinch those stems they will propagate easily.

Hey Wowbegonia! How have you been?

So, you've heard of Tripartita, Bonsia Begonia?

Have you ever heard of B. Richardsiana? 'sp.'
I bought one in the early 90's..Because the seller said Richard makes a good bonsai plant, once it arrived, I placed in a Bonsai container. It lived many years, then had problems after it fell in the sink. However, I always had cuttings handy, thankfully. I had to restart over. The Richardsiana is over 10" tall. But, it's in a regular pot, though small.

Do you know if Tripartita grow similar to Richardsiana?

Trip is near south and east windows, plus under artificial light. (Though neither south nor north is very bright)
I fear placing Trip in a sunnier location, 'especially once we get sun,' lol.

My Richardsiana lived/s in a north window, compact, and when it was potted in bonsai container, flowered.

So, are you saying I should wait before placing in a bonsai pot? Also, do I pinch the top? There are no side branches, only leaves. Thanks, Toni