I'm not sure if this information will be helpful, but below is a list containing some different types of Armoracia rusticana and information about them that I found on the web. There seems to be a lot of confusion about different types and contradictory information seems somewhat common.

'Big Top'- Vigorous and resistant to rust, bacteria spot, and some foliage diseases.

'Bohemian'- Hardy and easy to grow. Smooth good quality roots somewhat smaller than 'Common'. Susceptible to virus with some white rust tolerance.

'Bohemian Giant'- Hardy and easy to grow with large superior quality white roots. Susceptible to virus with some white rust tolerance.

'Maliner Kren'- Improved Bohemian type. Vigorous grower with large white roots. Earlier, larger, and whiter than standard types. Old plants tend to get woody.

'Swiss'- commercial strain of Bohemian type.

'Sass'- commercial strain of Bohemian type.

'Common'- Broad, crinkle-leaf variety. Susceptible to virus and white rust diseases.

'Hybrid'- Superior disease resistance, smoother roots, and larger yields.

'Variegata'- Less invasive with variegated leaves. Tolerates partial shade.

I ran into oodles of that contradictory info too. I'm still trying to figure out how they got hybrids if the seeds of horseradish never mature - unless they are genetically engineered? Burpee's has the Maliner Kren on their site and I *think* cites it as an heirloom... I found some sites with the variegated, which I am very interested in (because I'm a sucker for variegated plants) though I'd be happy with with "common"... I'm hoping that this one place will reply soon with my questions about their variegated (and some other plants and availability) and I'll be able to scrape up enough for a minimum order $/amount plus the flat rate shipping... they only have the variegated unfortunately. It would be easier if they had that and another type. I've been scouting produce sections for fresh roots as I know those can be planted... nothing so far, and neither am I finding it in the gardening sections even though many seeds and other things, like asparagus, etc. - are already in stock. I'm afraid it might be such a low-seller that I won't have a choice but to order unless someone else has some I can get some sets from.