Corolla
the inner whorl of two series of floral envelopes, occurring in the more highly developed plants. It is situated within the outer of these envelopes called the calyx, and exteriorly to the stamens and pistils. In all cases its divisions, which are called petals, alternate with those of the calyx. They are generally colored-i. e., in botanical language, they are some other color than green. The corolla is, as a rule, larger than the calyx, but in some plants this is not the case. When the petals of a corolla are all distinct, they are said to be polypetalous, which is the normal type of a corolla. When they cohere continuously by their margins they are generally called monopetalous (one-petaled), which is a not quite accurate term; a better one is gamopetalous, meaning that the petals have in a certain sense contracted what may be poetically called a marriage union. The petals of a corolla are really only modifications of leaves. The corolla is not essential to the reproduction of a plant. It shades the productive organs inside it from injury, and, in some cases, by secreting honey attracts bees and other insects to aid in their fertilization.