DOUBLE:

A flower with additional sets of perianth segments set one within the other ("hose-in-hose" style), and/or with the stamens converted to petal-like structures (petaloids). Also see: Perianth segments, Petaloid, Stamen.

"Super double": Having no functional stamens or pistils; usually with completely sterile petaloid stamens and duplication of petals or of petaloid stamens. Such a flower is fully sterile. Dr. Arlow B. Stout observed that he knew of no daylilies that met this definition.

"Para-double": Having at least some well-formed stamens or petaloids usually with some traces of anthers. Usually there is duplication of petals or petaloid stamens. There is abortion or sterilization of the pistil. Such a flower is sterile as a seed parent. Stout observed that H. fulva 'Flore Pleno' and H. fulva 'Variegated Kwanso' were the only two cultivars he knew that met this definition.

"Semi-double": Having only petaloidy of some stamens or occasionally of all stamens. Usually the pistil is normal. Nearly all flowers of this class are potentially fertile in respect to some stamens and the pistil.

"Psuedo-double": Occasionally some flowers of daylilies have more than the normal number of parts within each whorl in the flower. When such a flower has four petals there are usually also four sepals, four stamens in each of the two whorls and four carpels the pistil. There is further increase in the number of parts until it is obvious that there is fusion and fasciation involving two somewhat distinct flowers. In such flowers there are apparently sporadic and incidental rregularities in development and growth that are of doubtful or incomplete genetic value.