S: (n) corolla ((botany) the whorl of petals of a flower that collectively form an inner floral envelope or layer of the perianth) "we cultivate the flower for its corolla"
S: (n) calyx ((botany) the whorl of sepals of a flower collectively forming the outer floral envelope or layer of the perianth enclosing and supporting the developing bud; usually green)
S: (n) hull (persistent enlarged calyx at base of e.g. a strawberry or raspberry)
S: (n) pappus (calyx composed of scales or bristles or featherlike hairs in plants of the Compositae such as thistles and dandelions)
S: (n) thistledown (pappus of a thistle consisting of silky featherlike hairs attached to the seed-like fruit of a thistle)