perianth
1.. Of a flower, the outer covering, composed of the floral leaves, usually an outer greenish calyx, and an inner, brightly coloured corolla.

2.. Of a liverwort, a tube-like or purse-like sheath which surrounds the archegonium.

perianth The part of a flower situated outside the stamens and carpels. In dicotyledons it consists of two distinct whorls, the outer of sepals (see calyx) and the inner of petals (see corolla). In monocotyledons the two whorls are similar and often brightly coloured. In wind-pollinated flowers both whorls may be reduced or absent. In many horticultural varieties the number of perianth parts is multiplied, but the resulting `double' flowers are often sterile.

per·i·anth / ˈperēˌan[unvoicedth]/ • n. Bot. the outer part of a flower, consisting of the calyx (sepals) and corolla (petals).

perianth (bot.) †calyx, involucre XVIII; outer part of a flower XIX. — F. périanthe — modL. perianthium, f. Gr. PERI- + ánthos flower.

perianth Outer region of a flower. The perianth includes all the structures surrounding the reproductive organs and usually consists of an outer whorl of sepals (calyx) and an inner whorl of petals (corolla).