This is 'Kwanso':
it's less organized than 'Flore Pleno' and the latter has more of a layered petal look.
From Stout's early description in the AHS Yearbook 1957.
" The number of fully formed petals in flowers of Flore
Pleno usually ranges from 8 to 14 and the number of well-formed stamens usually ranges from 6 to O. The flowers of the Kwanso type show wide variation in the relative numbers of petals and stamens. Frequently the only well-formed petals are those of the primary or first whorl in which case
the number of poorly developed petaloids and normal and abortive stamens is high. Decrease in the number of bladed petaloids is accompanied by increase in the number of stamens. Often
in the flowers of Kwanso the petals and petaloids are much twisted and curled. "
