T clusiana
B.J.M. Zonneveld (Mon, 12 Nov 2007 02:32:54 PST)

T clusiana indeed range from diploid to pentaploid. I don't know if they
are in mixed populations. Only the pentaploid seems to have expanded as
far as Spain due to the fact it makes stolons. I suppose the diploid ( T
aucheriana) does not make stolons.
It is for sure that T clusiana has not contributed anything ( despite
some suggesting otherwise) to the gesneriana type cultivars of today.
They cannot be crossed and differ strongly in nuclear DNA content