DO you include a piece of stem. ?

Yes, a rhizomatous Begonia. Propagation for the type is the same regardless of leaf pattern. I've started over a dozen of this kind, both in water & directly in soil:

It is confusing when it is said as leaf propagation, but really is stem and leaf.

Yes, sort of, petiole & leaf. Rhizomatous Begonias don't have stems, each leaf (connected by its' petiole) comes directly from the rhizome. Some types of Begonia can be started from a piece of a leaf but I don't remember if rhizomatous ones are among those. Brad's Begonia World propagation page has pics & info.

Thanks for info !

My pleasure