Swingle produces a trifoliate leaf structure from the very begining. - Millet (1,260-)

I have seen trees from RB graft on Volk, or at least some sort of lemon. I am not sure if the leaves pictured are Volk or not, but if it puts out such leaves again, you can get a pretty good idea by crushing a few in you hand and smelling them. Lemon will have a lemon odor. Of course, there are other single leafed rootstocks, but I most often see Volk used. Most growers like to use lemon as a rootstock, because it makes a good healthy looking tree faster than other rootstocks, and for most retail customers, rootstock is not a consideration when buying a tree.

Another thing I have observed about most nurseries. They seldom reveal what rootstock they have used. A lot of times I am not even sure they know. You almost never see the rootstock listed on the tag and, if you ask, you seldom get a clear answer.

Ned

Some nurseries paint their trees with a painted strip of various colors. The color of the paint tells what the root stock variety is. This works well. When you call the grower and request the variety of the root stock, they ask if the tree has a paint stripe, and if so what color. Upon telling them the color they tell you immediately what the root stock is. The entire process takes less than one minute. Millet (1,260-)

For Ned, I got the leaves and crushed them. They smell kind of like lemon. I'll have to compare them to my lemon tree to be sure. I am guessing they didn't know, because they don't look like swingle and I described exactly what kind of tree I bought.

For Millet, It had no paint, but it had a blue piece of ribbon stapled around the rootstock (not into the wood, but wrapped around and stapled together)

It smells like lemon, it takes over the plant easily (I read that volk does that a lot), it's got serrated edges... I think you hit the nail on the head.

Zeeth, I am virtually certain Volck is what you have now. Actually, I imagine it will do alright for you, as long as you are careful to check for rootstock sprouts.

Ned