Through the 38 year period since this plant's introduction, several factors contribute to the true plant being mixed up in horticulture and the nursery trade.

1. While stated as having "little or no seed production", it will in fact make viable seed near the end of the flowering season. Hibiscus syriacus cultivars in general are prolific seed producers and they're easily grown from seed, thus regrettably many nurseries grow named cultivars from seed. Seedling progeny vary considerably from a named cultivar, often the progeny is inferior to the cultivar. I know this first hand growing thousands of plants in a Rose Of Sharon hybridization effort.

2. The true 'Helene' has an exceptionally bold red eye with radiating red lines that can reach mid-petal length. It has 3-20 petaloids in the center as mentioned in the first comment. These petaloids are missing in all photos except maroonmom's photo, although the red eye in that photo seems too small to equate with Helene.

3. Mix-up with other varieties, such as with the similar looking 'Red Heart', complicate matters.That variety produces prodigious quantity of seed. If one goes to a nursery when H. syriacus cultivars are in bloom, often one can spot lots of variation in both flowers and foliage, an indication they're seed-grown plants.

In this link of H. syriacus 'Helene', the flower looks like the true 'Helene', notice the presence of petaloids.
http://www.hydrotip.de/datenba...