MODIFICATIONS OF THE FLORAL ORGANS. 187 



Not unfrequently, however, the floral envelope which has 

 disappeared, has left traces of its existence sufficient to disclose 

 the character of that which remains. We know that the pro- 

 per place of the petals is between the sepals and the stamens, 

 and if we find anything occupying their position, we are at 

 once convinced from the laws of development which are so 

 clearly and beautifully expressed in other genera, that it is 

 the same organ in an abortive or rudimentary condition. Thus 

 the flower of Pulsatilla patens has only one floral envelope. 

 In the place, however, usually occupied by the petals, we find 

 certain abortive gland-like stamens, which are in fact the rudi- 

 ments of the suppressed petals; this therefore decides the 

 envelope to be a calyx. 



In some plants, such as nettles and Chenopodiums, the 

 floral envelopes are green and inconspicuous, and in the grasses 

 they are suppressed altogether, their places being supplied by 

 rudimentary leaves or bracts. When this is the case, the flower 

 ceases to attract popular attention. The world attaches the 

 idea of a flower to that part of a plant which is usually colored 

 with tints more or less brilliant, which makes its appearance 

 generally before the seed, and after delighting our senses with 

 its fragrance and beauty for a brief space of time, is replaced 

 by the fruit or seed. But such flowers are only characteristic 

 of the more perfect races of plants. The botanist stops not at 

 these appearances, for to him the flower is often deprived of 

 them. The student must learn to recognize the flower in the 

 lower degrees of its development. 



When both stamens and pistils are present in the same 

 flower, it is said to be hermaphrodite and complete. When on 

 the contrary, the flower contains stamens only, or pistils only, 

 it is denominated unisexual, and is male or female according 



