caducous

1. Most amphibians have caducous gills; the caducous calyx of a poppy.
   大多数两栖类动物都有早落腮；易脱落的罂粟花萼。

adj

1. shed at an early stage of development
   1. most amphibians have caducous gills
   2. the caducous calyx of a poppy

   Synonym:    shed