70 ORGANS OF REPRODUCTION CALYX. 



76. Tendrils are thread-like organs by which the plant at- 

 taches itself to neighboring objects. Whatever may be their 

 origin, if they correspond to the above definition, they are de- 

 nominated tendrils. In some plants they are modifications of 

 branches, as in the Vine, in others they are the extension of 

 the midrib of the leaf, as in the Vicia and Pea, in others mod- 

 ifications of the Stipule, as above noticed. *Tis said that the 

 petals sometimes become tendrils and support the plant, as in 

 the genus Strophanthes, an African plant. 



CHAPTER III. 



77. The Organs of Reproduction compose ih^jiower, which 

 consists generally^f the Calyx, Corolla, Stamens and Pistils, 

 Although all of these organs enter into the composition of 

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

 all be present. A perfect Jlower is one that has stamens and 

 pistils, without reference to the presence of the calyx or corol- 

 la. When these latter organs are wanting and the stamens 

 and pistils have no envelops the flowers are said to be ach- 

 lamydeous or destitute of covering, as the word signifies, at 

 others they have a single envelop and are said to be mono, 

 chlamydeous, or having a single covering and this envelop is 

 called the calyx ; at other times, they have a double envelop 

 and are called dichlamydeous, or having a double covering, 

 in this last case the outer envelop is called the calyx, and the 

 inner the corolla. By strictly adhering to the above defini- 

 tions, all flowers, which do not have a double envelop, have 

 no corollas whatever may be the appearance of the envelop 

 which is present. The Lily, Anemone and many other showy 

 flowers, have correctly speaking no corolla. It is not un- 

 frequently the case, that there are several rows of envelops 

 and so nearly of the same constitution and appearance as to 

 be undistinjTuishable from each other, in such cases the calvx 

 an! corolla are said to be confounded, that is, they cannot be 

 distinguished as in the Calycanthus and the whole is called in 

 such cases a perianth. 



78. 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 envelop 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 



