Shimpaku is chinensis, chinensis is not necessarily shimpaku. Shimpaku is just the word the Japanese use to describe their own specific varieties of chinensis such as Itoigawa and Kishu.
Bjorn breaks it down pretty well…So "shimpaku" refers to any Japanese Chinese juniper? I guess "Japanese Chinese juniper" is a confusing mouthful to say, so it makes sense to use the Japanese word for Chinese junipers when referring to Japanese Chinese junipers.
See the resources part of this forum for an oveview of the Juniper species and everything should be clear.
Juniperus chinensis - Chinese Juniper. Native range is Japan, Korea, China, and Mongolia.
Link: https://www.bonsainut.com/resources/juniper-species-varieties-and-cultivars.26/
- Juniperus chinensis subsp. sargentii- Sargent's Juniper; Shimpaku
- Juniperus chinensis subsp. sargentii var. Itoigawa
- Juniperus chinensis subsp. sargentii var. Kishu