Blue Rose, Humble But Especially Lovely Old Watercolor

Just a single bloom, but this is among my favorite watercolors of late, just a small perfect thing. A blue rose I believe, labeled what looks like "japonica," which is indeed a type of rose--the Kerria japonica, but that as far as I can tell is yellow...  Blue roses are in fact often used to symbolize mystery or the unattainable, since they do not exist in nature because of genetic limitations, so perhaps here the unattainable manifested!

7" x 5", very good condition.