telling apart species of comfrey (esp. british ones)?

Question

symphytum ssp.
any ideas that don't involve carrying a microscope around? its probably not that difficult. I just never really tried to learn because they do look very similar.

Answer 1

Symphytum caucasicum Caucasian Comfrey 18-24" blue flower S. grandiflorum Large Flowered Comfrey 12-15" yellow S. rubrum Red Comfrey 15-18" Red S. X uplandicum Russian Comfrey 36-48" blue

Answer 2

Strange and incomplete question if you ask me. Here is the comfrey wiki:
http://en.wikipedia.org/wiki/Comfrey
and they state there are several species. You sound lazy so I will give a lazyman answer: What difference will it make if you misidentify the plant species? The layman normally doesn't care and if you want to be among botanists you better crack open the books and practice identifying it yourself.

Notice in the wiki article they state why the russian comfrey was planted in England. Fortunately since most are grown by vegetational methods there is not too much interbreeding but there is a possibility so learning to recognize species may be too difficult anyways....