Det är luftrötter. Vi fick det här svaret från JUB:

It is not uncommon for Fritillaria imperialis to form roots during dormancy although rarely this early in the season.

Do not worry, these roots, we call them air roots here in the Netherlands, do not form any threat to your bulbs. After planting the bulb will form new, thinner roots and these air roots will disappear.

Best thing to avoid these roots is storing the bulbs at a temperature of 25 degr. C. This is what we do in our warehouse, and we have not seen any change in our stock.

So please, do NOT store your Fritillaria imperialis bulbs cooler than the 15 degr. C that you mentioned. This will probably increase the “problem” more.

Also please notice that Fritillaria imperialis needs a different storage temperature than Fritillaria meleagris. F. meleagris is a completely different species and this does need to be stored at low temperatures (5 degr. C)