If the leaf continues to spiral over another leaf I believe they call this form E. Helix.

Yes, Woe is correct on a curly leaf but it seems like it should be more than that what I see in the OP's photos. The common name is Curly Beefsteak. Some advertise it on eBay as 360 or 720 degree beefsteak (hmmm?)

Here is one of mine from 3 years ago. I don't know if I even have it any more.

Thanks!!!

Awesome! One of my first begonias from long, long ago. I want to get Beefsteak back so bad.

So I'm not having luck at getting the rhizome to stay in the soil. Any advice? They seem to want to lift up, not touching the soil. I've tried putting more soil in the pot, like filling it all the way up, with no luck. It's like the soil isn't heavy enough to hold them in place? I'm using plain o' Miracle Grow. Any advice? Thanks.

Could you get a length of wire and shape into a 'U'? Make it almost long enough to reach pot bottom then peg rhizome to soil surface.

Kyle has a good idea. I typically put a large rock either on the rhizome or close to it. This helps in two ways - 1) puts an anchor on the plant until it roots and can be on its own and 2) discourages squirrels from digging in fresh soil.

This photo is not a begonia and is not to weight down a plant for rooting but is showing caladiums coming up around pottery shards (for discouraging digging rodents)

These are exceptionally big rocks to hold some broken off stems of popenoei a few years ago
more broken shards holding a big fat rhizome of something in place.

rocks in a pot of carolineifolia

I am trying to do a bonsai pot with a broken stem of Selph's Mahogany indoors. The stem was leafless for weeks and the broken end rotted off. I sparingly watered it and put a moat of water around it and covered with a dome. Once it rooted and leaves came on, it started to flop over so I now have the rhizome propped up with some large decorative stones.

one final example of this big Immense plant held in place with a good size rock in a pan of perlite.

I use rocks also sometimes especially if the peg won't stay pegged.

Another reason to use rocks is to give the pot some weight so it won't blow away or get tipped over easily (if outdoors that is).

I guess a stake would work well too but I've not used any for rhizomatous.