THE PARTS OF THE PISTIL 57 



flowers which have all the four parts are quadriserial ; those lacking 

 only the calyx are triserial; those lacking the floral envelopes are bi- 

 serial; and those which contain only the pistil are uniserial. 



706. It is customary, however, to speak of flowers which lack the 

 calyx as asepalous ; and of those which lack the corolla as apetalous. 

 When flowers lack both the calyx and corolla (as the willows), they 

 are said to be naked, or achlamydeous. 



70c. Flowers which contain pistils and no stamens are said to be 

 pistillate, or fertile. Those which have stamens and no pistils are 

 staminate, or sterile. In common language they are sometimes said to 

 be female and male, respectively, but the former terms are better 

 when speaking of the parts as facts (or as members), without refer- 

 ence to sexuality. When pistillate or staminate flowers are spoken of 

 without designating which they are, they are properly said to be di- 

 clinous ; which is essentially the same as to say that they are imper- 

 fect, as this term is generally used. They are sometimes said, also, 

 to be unisexual, in distinction to bisexual or hermaphrodite flowers 

 (which have both stamens and pistils). 



70d. When speaking of the staminate portion alone, it is custom- 

 ary to call it the androecium ; and to call the pistillate portion the 

 gynoecium. 



SUGGESTION. The pupil should now have practice in distinguishing 

 the members or parts of flowers, and in interpreting the unusual or 

 disguised parts. 



XII. THE PARTS OF THE PISTIL 



71. The pistils of hepatica, mustard, tulip 

 (Fig. 49), and willows are composed of a 

 single straight column. The mustard and wil- 

 low have a distinct style, but the hepatica and 

 tulip differ in having none. That is, the stigma 

 is often sessile on the ovary, from which we 



