Hello dear @gwajnberg, banana is a crop that propagates only by vegetative seed, when we refer to vegetative is that a part of the plant is used, in this case it is the underground stem called rhizome, those who work with banana also call it corm. In the following link we talk a little about it:

@amestyj/el-cultivo-de-platano-capitulo-iii-establecimiento-del-cultivo

Some children of the plants can also be collected to be transplanted into other spaces within the surface.

So long, have a great weekend.