PARTICULAR TYPES OF FLOWERS (ORCBIDS) 223 



255. The essential organs of a cultivated 

 cypripedium are shown in Fig. 214. Two anthers 

 are at a a. A petaloid body representing a third 

 stamen stands above them at &. This is known 

 to represent a stamen, because in most orchids 

 this uppermost body is a' fertile anther and the 

 lateral bodies are rudimentary. The lip -like body, 

 c, is the stigma. In Fig. 213 this staminodium 

 (230a) is represented by the ladle -like body pro- 

 jecting into the sac at h. 



256. The most important thing to note about 

 these essential organs is the fact that they are 

 united into one body. That is, the stamens and 

 pistil are grown together, or are said to be gy- 

 nandrous. The body formed by this union is tech- 

 nically known as a column; and it is the chief 

 distinguishing mark of orchids. 



256a. Orchids are plants with irregular trimerous flowers, usu- 

 ally one-loeuled inferior ovary and three parietal plaeentse, and g\ - 

 nandrous stamens, of which one or more is sterile. One of thfe 

 petals, or inner divisions of the perianth, is often sac-form. There 

 are about five thousand kinds of orchids known, most of which are 

 herbs. They chiefly inhabit the tropics, but there are many humble 

 and local species in the northern United States and Canada, grow- 

 ing in woods and bogs. In the tropics many of them are epiphytes 

 (growing upon trees^, and in the North some of the species are 

 saprophytic on the roots of trees, and are destitute of foliaeeous 

 leaves. Numbers of tropical species are cultivated in glass houses. 

 Among the better known plants which are members of the Orchi- 

 dacesB are the lady's-slippers or cypripediums, rattlesnake plantain, 

 putty- root and vanilla. 



