FLOKAL ENVELOPES 



123 



lobed or divided, in which case the divisions are called 



calyx -lobes. In like manner, the corolla may be com- 

 posed of petals, or it may be of 



one piece and variously lobed. A 



calyx of one piece, no matter how 



deeply lobed, is gamosepalous. A 



corolla of one piece is gamopetal- 



ous. When these series are of 



separate pieces, as in Fig. 187, the 



flower is said to be polysepalous . 



and polypetalous. Sometimes both 



series are of separate parts, and 



sometimes only one of them is so 



formed. 



252. The floral envelopes are 



Jiottwlogous with leaves. Sepals and 



petals, at least when more than 



three or five, are each in more than 



one whorl, and one whorl stands below 

 another so that the parts overlap. 

 They are borne on the expanded or 

 thickened end of the flower-stalk: this 

 end is the torus. In Fig. 187 all the 

 parts are seen as attached to the torus. 

 This part is sometimes called recep- 

 tacle, but this word is a common- 

 language term of several meanings, whereas torus has no 



other meaning. Sometimes one part is at- 

 tached to another part, as in the fuchsia 



(Fig. 189) in which the petals are borne 



on the calyx -tube. 



189. Flower of fuchsia in section. 



190. Pistil of garden pea. 

 the stamens being pulled 

 down in order to disclose 

 it; also a section, showing 

 the single compartment. 



253. ESSENTIAL ORGANS.— The essential 



Simple pistils of 

 ;ercup, one in 



organs are of two series. They are also longitudinal section, 

 homologous with leaves. The outer series is composed of 

 the stamens. The inner series is composed of the pistils. 



