Thanks, johnnieb - I have grown that variety for years, and it's a great performer here, having become a veritable weed (albeit a good one), along with several Sinningias, Achimenes, and oddballs like Titanotrichum, Hemiboea, and Lysionotus. S. sylvatica returns and grows pretty well, but rarely blooms in time to escape frosts, which is why I was excited about getting this plant. It's still blooming, btw, so I'm hopeful.

I haven't had luck with any achimenes or seemannias surviving even a mild winter. :o(

BTW here's another photo of my S. nematanthodes 'Evita' taken yesterday--it has been blooming its head off!

It looks great - I love this plant for the way it scrambles all around and fills in gaps. It's kind of a "good" weed here. We're probably a bit warmer than you, so maybe that makes the difference re. the Seemannias and Achimines. They're all pretty late to emerge, and I always save a few rhizomes for insurance purposes. If it's any consolation, your hostas look better than mine at this point!

Where can I buy Seemannia Sylvatica plant?

You can buy plants, you can buy rhizomes, you can buy seeds. Winter - is a poor time for buying freezable material, but comes spring - you will find rhizomes and plants on ebay and from other vendors. Right now I see Seemannia "Medea" at Violet Barn. As far as I know It is not a species, it is an interspecific hybrid with S.sylvatica as one of the parents. I think it is more compact. Great cultivar.

https://www.violetbarn.com/cart/other-gesneriads/miscellaneous-gesneriads/seemania-medea.html

But if you are desperate to get it now - you will need to pay for winter shipping.

I am pretty sure that if you join the Gesneriad Society - you can get seeds of it from their seed fund.