There are several species of hibiscus, but in general, "hardy hibiscus"
or perennial hibiscus is the name used here in the midwest for 2
different species of herbaceous hibiscus- Hibiscus moscheutos, and H.
coccineus. Both are sold at nurseries everywhere as perennial
hibiscus, though H. moscheutos is much more common. Hibiscus syriacus,
which is a hardy woody shrub, is also extremely common here and is
usually sold under the name "rose of sharon" or "althea". Your indoor
plant is most likely a variety of the tropical Hibiscus rosa-sinensis.
It can be confusing sometimes, and this is a perfect example of why
using common names for plants is not usually an effective way of
identifying them.

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