I'm entertaining myself on a rainy day by trying to figure out what some of my mystery plants are. These were grown from a gesneriad mix.
Can't be certain, but it may be Kohleria.
How 'bout sinningias? There are a lot of slipper-shaped flowers in gesneriads. That second one especially looks like a smaller sinningia. I could well be wrong, but I don't know of any violet/blue kohlerias.
Yes, look like sinninigias.
Do they have tubers?
Check on the Gesneriad web - there are lots of pics.
Here is a link that might be useful: Gesneriad Web
Many thanks everybody, for the suggestions and the link! Yes, the plants do have tubers, and I think you're right that they are sinningia types. The lighter colored one looks quite a bit like sinningia eumorpha photos I found at the Gesneriad Web link, and the purple one appears similar to several of the sinningia speciosa types shown. So at least I can label them as something more specific than "unknown gesneriad!"