Compound plants in the VMS ?

[Linda]

Some of the plants, for example f19v, f39v, show clear discontinuities between root and stem, i.e. a flat section at the top of the root with the stem apparently separate but 'stuck into' the root. Most plants in the VM do not look like this, they have continuous root-to-stem, even if the colour changes and the root bulges or flattens before the stem. 

I wondered whether these root-stem discontinuities might represent grafting, where a scion (the young shoot of a plant) is grafted onto a different rootstock? 

I see it rather as a plant regrown from a bare root. The resulting plant is generally smaller in girth than the exposed root would lead one to estimate initially, in many cases it leads to multiple shoots, which, if you cut them off to concentrate on a particular new stem or leaf appendage, or naturally sets out only one such shoot, could possibly result in a similar size change at the stem/root join.