I think what you have is one of the reproductions made after Roseville went out of business in 1954 !! Everything after 1931 by Roseville was marked with USA immediately below the name with the size and style number !! Only time they ever left USA off of their pottery was between 1932 and 1937 and then the name was incised into the bottom not raised !! The space between the name and the size/style numbers is where USA should be but was left off of the reproductions since according to US law imported items must have the country of origin which is usually China !! That was done with a stick on label !!
Then there is the color,, zephyr lily was only made in three colors,,Bermuda Blue,Evergreen and Sienna which is a brown and all were shaded on the main body !! Only time black was ever used by them was prior to 1920 and with the Rozanne Ware line !! It was not called Roseville back then !! In looking at your piece I see enough chipping of the paint to suspect that your ewer was painted at some point !! Perhaps it didn`t go with someones decorating scheme !!
I have looked for other reproductions made in black and have found none
