At the base of petals on R. chinensis spontanea

Cass has posted some magnificent detailed photos of R. chinensis spontanea (one, in particular, is linked below).

Would anyone else take a look at the two blooms in the lowermost right hand side of the photo and see a darkened coloration at the base of the petals?


They created tetraploid persicas … .

Only question to me: are those plants really fertile?

As they took no persica hybrids, but the mother herself … .