Is goldenrod a common noun or a proper noun?

The Word goldenrod is a common noun, a Word for any goldenrod.

A proper noun is the name of a person, place, thing, or a title; for example:

• The Goldenrod (candy store), York Beach, ME
• Goldenrod, FL
• Goldenrod Street, Escondido, CA
• Goldenrod Print & Mail, Lincoln, NE