It is hard for me to keep all this "redpoll" stuff sorted (maybe it is for some of you also). At any rate here is some information I gleaned from "googling" the internet.
Here in the US we get:
1. Common Redpoll (aka. Mealy Redpoll), Carduelis flammea
2. Hoary Redpoll (aka.Arctic Redpoll), Carduelis hornemanni
The three races of redpoll found in Britian are:
1. *The British race, Lesser Redpoll, Carduelis flammea cabaret
2. In northern Europe, the Common (Mealy) Redpoll, Carduelis flammea flammea
3. In Greenland, the "Greenland" Redpoll, carduelis flammea rostrata
* Lesser Redpoll, C. cabaret is now widely treated as a separate species from Common Redpoll, C. flammea cabaret
Four races of Common Redpoll (aka. Mealy Redpoll) exist:
Carduelis flammea flammea: found across the Arctic, with some to the south in Newfoundland and central Russia. This is the one most frequently found in North America during irruptions.
Carduelis flammea rostrata: found in Greenland, is larger and browner than Carduelis flammea flammea.
Carduelis flammea cabaret: Found in Europe, this is the smallest race of Common Redpoll.
Carduelis flammea islandica: found in Iceland.
There are two supspecies of Hoary Redpoll (aka. Arctic Redpoll)
Carduelis hornemanni hornemanni: the Greenland form, breeds in high Arctic of Greenland and Canada. It is very pale.
Carduelis hornemanni exilpes: this is the southern form and it breeds in Canada, Alaska and Eurasia.