If I'm interpreting the ICNCP correctly, a common name could be included in a cultivar name for the same plant if established prior to 1959. What I was trying to say was that Mobot considered it a cultivar a. by saying so, and b. by using single quotes, which designate a cultivar under the ICNCP. I agree it would be better to have it under the cultivar name 'Purpurea', although the Royal Horticultural Society also gives 'Purple Heart' as a synonym - not sure if this link to their page for it will work:
https://www.rhs.org.uk/Plants/...
You may have to click on "See more" under synonyms
