Yes, a poly can love a mono and a mono can love a poly. The real issue is: Can the mono ever fully accept the poly's relationship style.
Poly is hard enough between all poly people, but adding someone with a monogamist mindset can be downright difficult if not impossible sometimes. Mainly because many times a mono person will want the poly to be mono and they either consciously or unconsciously try to turn the poly person to mono with them. They can't help it, it's how they are hardwired.
Some mono's will think in the back of their mind that a poly will change once they get in a relationship with them, or that they can change a poly to mono. And in turn, a poly may think that they the mono person will become poly for them once they are in a relationship.
Then there is jealousy. Jealousy exists in poly's who are open relationship-minded, and exists to the umpteenth degree amongst many monogamist-minded individuals. Expect that they will be jealous of your other partner(s).
So yes, it is possible, but in my experience it will require more work and more patience than simply sticking to poly-minded people to have a poly relationship with. So be prepared if you pursue a mono person to be in a relationship with.