62 ORGANS OF REPRODUCTION CALYX. 



102* Tendrils (Fig. 94) are thread-like organs, by which the 

 plant attaches itself to neighboring objects. Whatever may be 

 their origin, if they correspond to the above definition, they 

 are denominated tendrils. In some plants, they are modifica- 

 tions of branches, as in the Vine; in others, they are the exten- 

 sion of the midrib of the leaf, as in the Vicia and Pea; in 

 others, modifications of the stipule, as above noticed. It is said 

 that the petals sometimes become tendrils, and support the 

 plant, as in the genus Strophanthes, an African plant. 



CHAPTER III. 



103. The Organs of Reproduction compose the flower, 

 which consists generally of the calyx, corolla, sta?nens, and 

 pistils. Although all of these organs enter into the composi- 

 tion of most flowers, yet it is by no means necessary that they 

 should all be present. A flower consists of one or more whorls 

 of modified leaves, arising from an axis whose internodes are 

 not developed. All the organs of reproduction are simply 

 modified leaves. A perfect flower is one that has stamens and 

 pistils, without reference to the presence of the calyx or corolla. 

 When these latter organs are wanting, and the stamens and 

 pistils have no envelopes, the flowers are said to be achlamy- 

 deous, or destitute of covering, as the word signifies. They 

 have sometimes a single envelope, and are said to be mono- 

 chlamydeous, or having a single covering, and this envelope is 

 called the calyx. At other times, they have a double envelope, 

 and are called dichlamydeous, or having a double covering. In 

 this last case, the outer envelope is called the calyx, and the 

 inner the corolla. By strictly adhering to the above definitions, 

 all flowers which do not have a double envelope have no corol- 

 las, whatever may be the appearance of the envelope which is 

 present. The Lily, Anemone, and many other showy flowers, 

 pave, correctly speaking, no corolla. It is not unfrequently the 

 case, that there are several rows of envelopes, and so nearly of 

 the same constitution and appearance, as to be undistinguish- 

 able from each other. In such cases, the calyx and corolla are 

 said to be confounded ; that is, they cannot be distinguished, 



102. What are tendrils? — 103, What are the organs of reproduction? 

 What is a perfect flower? When achlamvdcous 1 When nionoehkuny- 

 deous? What called? When dichlamydeous? What called? When 

 arc the envelopes said to be confounded i What is it called ? 



