On Thu, 23 Jul 2015 09:37:12 +0100, Bob Hobden wrote:

I wonder what would happen using a Sycamore (Acer pseudoplatanus)
seedling as the rootstock?

Wrong section of the genus. Grafting inter-section is a dicey business
in Acer and doesn't usually work. This said, pseudoplatanus is sometimes
considered "universal understock" so it might work once in a while. (For
grafting species that don't have a suitable in-section understock
available, pseudoplatanus is sometimes used, but there is a very high
failure rate).

Acer is a complicated species, you can look at the wiki page to get some
idea of this but they've over-complicated by including extinct species
and is neither accurate nor up to date taxonomy-wise.

https://en.wikipedia.org/wiki/List_of_Acer_species

Before anyone asks: some of the "evergreen" species (e.g. sempervirens)
are deciduous in our climate, some synonyms are double listed (e.g.
ceriferum=robustum) and some species are named 20 years out of date (e.g.
nigrum has been called saccharum ssp nigrum since de Jong's 1994
classification anyway)



--
Gardening in Lower Normandy