I would love to know if this flower frog is a Roseville, if not who made it? Help!!

I have boxes of old pottery my father collected. This one I am partial too but haven't looked at it in 25 years..Now i'm wondering if it is a Roseville or I just want to lnow who made it..
It has a blue underglaze 'X'.. it is a pretty olive green with brown texture and sculpted leaves at the top..it's is stunning..I almost sold it for 25 cents at my garage sale years ago but pulled it out because it is so pretty.
Does any one have any idea who made it and what pattern it is..thanks!
It measures 4 5/8'' w x 3.5''h..