An article by Warren I. Pollock in The Hosta Journal (1985 Vol. 16) states that, "In a private garden in Uppsala, Sweden, Hylander found a hosta that he named H. fortunei 'Obscura'...Hylander didn't explain why he selected the name "obscura," but I would guess that it refers to the hosta's obscure origin...In the same garden Hylander found a handsome yellow-margined form...he named H. fortunei 'Obscura Marginata'...in Europe, it is called H. fortunei 'Obscura Marginata' and also H. fortunei 'Aureo-marginata', although in Britain the names 'Yellow Edge' and 'Sprengeri' have been used on occasion

...In the U.S., this hosta goes under three names: H. fortunei 'Obscura Aureo-marginata', 'Aureo-marginata' and 'Golden (or Gold) Crown'. I was told by one nursery that they sell the same hosta under any of these names."

Nomenclature changes recommended in the 1991 book The Genus Hosta by W. George Schmid and accepted by The American Hosta Society would update names as follows: H. fortunei 'Obscura' is now H. 'Fortunei Obscura' and H. fortunei 'Obscura Aureomarginata' would be H. 'Fortunei Aureomarginata'

To summarize all of these name changes:

1) H. fortunei 'Obscura' = H. 'Fortunei Obscura'
 

2) H. fortunei 'Obscura Marginata' = H fortunei 'Aureo-marginata' = H. 'Yellow Edge' or H. 'Sprengeri' = H. fortunei 'Obscura Aureo-marginata' = H. 'Golden (or Gold) Crown' = H. '
 Fortunei Aureomarginata'.