hello i'm new on this forum. i am looking for "davidia involucrata sonoma" please send me a message if you know where i can find it.
When it was offered on the website of Sonoma Horticultural Nursery it was listed as 'SH1'. The garden there houses the tree upon which the cultivar was based. Perhaps it has not been put into commerce overseas. Have you been watching annual listings in RHS Plant Finder to see if it has appeared in that publication? Both print copies and web site listings (rhs.org) are produced.
Probably not available in Europe. It is a fairly recent cultivar from North America, dating from after the time when phytosanitary regulations were made much stricter, prohibiting the movement of live plants between continents. So it would be illegal to bring it into Europe.