As far as I know perilla is the genus and the species and shiso is a variant of it, or another name. They are very similar. How to Cook With Perilla and Shiso, the Super-Fragrant Herb We Can't Stop Eating, Perilla frutescens is the species.
Last year I grew perilla in my boxes. I subbed it for shiso numerous times. If there is a difference it is too subtle for me to discern. It is delicious, especially wrapped around galbi. For what its worth I offer this - enough conflict these days without debating plant names.
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