Here are two vintage clip art illustrations of the Moutan Peony. Fig. 3 represents a single-flowered, and Figure 4 a double-flowered, variety of this beautiful species. 
The illustrations are from the Illustrated Dictionary of Gardening – A Practical and Scientific Encyclopedia of Horticulture, edited by George Nicholson, circa 1885.
Click on images to enlarge.
Thank you
Beautiful! Thank you
You’re welcome, Kim. I’m happy to know you like them. 🙂