COROLLA. 63 



as in the Calycanthus, and the whole is called in such cases a 

 perianth. 



104. The word calyx is derived from a Greek word (calux), 

 which signifies a covering, and is a generic term applied to 

 designate every form of the external envelope which surrounds 

 the stamens and pistils. The general distinguishing charac- 

 teristics of the calyx are — that it is the outer covering of the 

 flower, green, smaller than the corolla, more firmly attached to 

 the plant, and having more the appearance of leaves. Although 

 the above may be considered as designating this organ in most 

 plants, yet there are numerous exceptions to it. The first part 

 of the definition, that it is the outer covering, is the only charac- 

 teristic that never varies. It is sometimes even more brilliant 

 in its colors and larger than the corolla itself, and instead ot 

 being more permanent, in some species of plant it falls even 

 before the corolla expands ; but these are exceptions to a general 

 fact. 



105. When the calyx consists of a single piece, it is said 

 to be monosepalous, or gamosepalous — the latter a term invented 

 to indicate the union of several sepals in forming the calyx. 

 Each leaf of the calyx is called a sepal. When it is composed 

 of several distinct leaves, it is called pohjsepalous. In the 

 gamosepalous calyx, that portion formed by the union of the 

 sepals is called the tube; the expansion at the top is called the 

 limb. If the calyx takes its rise below the ovary or seed-ves- 

 sel, it is said to be inferior ; if from the summit of the ovary, 

 it is said to be superior. The origin of the calyx, in both cases, 

 is undoubtedly the same — that is, from beneath the ovary ; but 

 in the superior calyx it becomes firmly united to the ovary, and 

 forms a part of it, as in the Apple. The Rose and a few other 

 plants form exceptions to the above, as what appears to be the 

 cup-like calyx of the Rose is considered an expansion, or hollow- 

 ing out, of the summit of the pedicel in which the calyx is 

 situated. 



106. Corolla. — As we above remarked, when there are two 

 floral envelopes, the interior is called the Corolla. A corolla 

 is said to be regular when the parts are equally and uniformly 

 developed on all sides of the center of the flower. The divi- 

 sions of the corolla are always alternate with those of the calyx. 



104. What is the calyx? What are its characteristics? Which never 

 varies? How with the others?— 105. What is each leaf of the calyx 

 called ? When the sepals are united into one piece, how is the calyx 

 said to be? When composed of several pieces? When inferior? Supe- 

 rior ? How in the Kose ?— 10G. What is the corolla ? When is it regular ? 

 How are the livisions of the corolla and calyx in relation to each other? 



