Courtesy of Royal Botanic Garden, Edinburgh
Monophyllaea is an Asian species (Malaysia, etc.) with a single leaf, from from the base of which arise multiple flower stalks. While it is not closely related to Streptocarpus, convergent evolution has produced strikingly similar-looking plant habits. For instance, see this photo of a single-leaf Streptocarpus growing on a tree trunk (as is this Monophyllaea). Other photos of Monophyllaea in flower can be seen here and here.