What are the large pink and white flowers I see around the Philadelphia area that look to me like giant hollyhocks?
There are some in the garden of the Radnor Hotel, and I see them in yards around the Main Line.
Answer
Hibiscus, in the Mallow family, known commonly as rosemallow, fits your description. Flowers are huge on a large shrub. To be sure, why not phone the Radnor Hotel and ask them.
If you google Hibiscus you will be able to see pictures of this flower.