Several years ago I purchased a rather nice tree peony. The ID tag only listed it as No. 27. It would be nice to know what its real name is.

There's a lot of tree peonies. It is rather nice!

I don't know where in the world you live, location can help to narrow down possibilities but some varieties will be popular anywhere.

I looked for one with bronze foliage as I can see it has some.

Paeonia 'Yachiyo Tsubaki' has bronze foliage.. read the description on the link..

http://www.kelways.co.uk/produ...

https://chartwellgardensnt.wor...

http://forum.jardinage.net/vie...

The new attached image gives a better view of the leaves. I am not sure that they are the same as the ones in the references you supplied. What do you think?

I don't know much about paeonia, but does petal count make a difference?

To be honest, I would think so. However, I really don't know. Maybe an expert will chime in.

Using the information supplied by JRsbugs, I looked at images of Paeonia 'Yachiyo Tsubaki' on dozens of websites and it seems that the mystery of No. 27's proper name is now solved.

Thanks JRsbugs

Bronze foliage isn't usual, with the flower colour, petals and wide availability (widely sold plants are usually good ones) seems to cinch it.

Depending on where No. 27 came from, it could be a numbered seedling from a person's hybridizing program. I don't know that that tree peony 'Yachiyo Tsubaki' was ever called No. 27. But they are certainly similar indeed.

Your mystery peony No. 27 is P. 'Hanakisoi'. I bought one last August from K. Van Bourgondien & it arrived with the No. 27 hang tag & Hanikisoi printed on a stapled paper band around the main stem. The owner of Peony's Envy, Kathleen Gagan, posted an Instagram video the 2nd week of May '22 during peak tree peony season & highlighted Hanikisoi so I had to buy one.