126 



THE PARTS OF THE FLOWER 



stamens nor pistils : these are sterile (snowball and hy- 

 drangea). Those which have both stamens and pistils are 

 perfect, whether or not the envelopes are 

 missing. Those which lack either sta- 

 mens or pistils are imperfect or diclinous. 

 Staminate and pistillate flowers are im- 

 perfect or diclinous. 



258. Flowers in which the parts of 

 each series are alike are said to be regular 

 (as in Figs. 187, 188, 189). Those 

 in which some parts are unlike 

 other parts of the same series are 

 irregular. The irregularity may be 

 in calyx, as in nasturtium (Fig. 195); in corolla 

 (Fig. 196, 197); in the stamens (com- 

 pare nasturtium, catnip Fig. 197, sage) ; 

 in the pistils. Irregularity is most fre- 

 quent in the corolla. 



198. Improvised stand 

 for lens. 



? 



Review. What is the flower for? What 

 are the two general kinds of organs in the 

 flower? What is the homol- 

 ogy of the flower- parts ? 

 What are floral envelopes ? 

 Calyx ? Sepals ? Calyx- 

 lobes ? Corolla ? Petals ? 

 Corolla-lobes? Gamosepal- 

 lous flowers ? Gamopetalous ? Poly- 

 sepalous? Polypetalous? Define torus. 

 What are the essential organs? Sta- 

 men? Filament? Anther? Pollen? 

 Pistil? Style? Stigma? Ovary? Car- 

 pel ? Define a complete flower. In 

 what ways may flowers be incomplete? 

 Explain perfect and imperfect (or diclinous) flowers. Define regular 

 flowers. In what ways may flowers be irregular? 



Note. One needs a lens for the examination of the flower. It 

 is best to have the lens mounted on a frame, so that the pupil has 

 both hands free for pulling the flo.ver in pieces. An ordinary pocket 



199. 



Dissect- 

 ing needle. 

 Vi natural 



size. 200. Dissecting glass 



