Nearly all the native American species should do fine in Maryland given proper siting and soil. There are several online nurseries with many to choose from. "Cultivar" has become a somewhat imprecise term. There are a great many named native azaleas which were selections from the wild with larger, brighter blooms, increased vigor and adaptibility, etc. They are propagated by cuttings when possible or by careful cross pollination to insure that seed grown offspring are identical to the parents. They are not hybrids and just as "woodsy" and just as much a straight native species as any dug in the wild.