Sinningia tubiflora
Sinningia tubiflora, the trumpet-flowered sinningia, is a species of flowering plant in the family Gesneriaceae, native to Argentina, Paraguay and Uruguay in South America. Growing to  tall and broad, this tuberous, mound-forming herbaceous perennial has silver-green leaves. The reddish stems appear in summer. Up to , they bear narrowly cylindrical white flowers, flared at the tips. The flowers may be  long, and are slightly scented. This plant is grown as an ornamental, for a sheltered spot (minimum temperature ) in sun or partial shade. It prefers a neutral or acid soil. Synonyms
Plants of the World Online  lists six synonyms:

Achimenes tubiflora 
Dolichodeira tubiflora 
Gesneria tubiflora 
Gesneria tubiflora 
Gloxinia tubiflora 
Houttea tubiflora

References

Flora of Argentina
Flora of Uruguay
Flora of Paraguay
tubiflora
Taxa named by Karl Fritsch