Juniperus virginiana is a species of juniper native to eastern North America, from southeastern Canada to the Gulf of Mexico, east of the Great Plains. In its native range, it is commonly called "cedar" or "red cedar," names rejected by the American Joint Committee on Horticultural Nomenclature as it is a juniper, not a true cedar.
This one pictured is from a rocky slope in Northern Kentucky. This type of juniper is rarely seen in bonsai. Next spring this plant will be placed in a smaller pot. For sale.