MANUAL OF NATURE STUDY. 149 



ready for action. The stigma and pollen must rip- 

 en at the same time, else self-fertilization can not 

 occur. See Gray's Structural Botany, pages 216- 

 242. 



In regard to the coalescence of the parts of the 

 floral envelope, it will be well to require seventh 

 grade pupils to learn the botanical names. When 

 the whorl of petals is more or less united, the cor- 

 olla is Q.zS\.<t$igamopetalous, a name signifying grown 

 together. When not united, or when the petals are 

 separate to the very base, the corolla is called 

 polypetalous^ a name signifying many separate 

 petals. 



When the outer whorl of the floral envelope is 

 united throughout any part of the sepals, above the 

 point of insertion, the flower is ca}^&&.gainosepalous. 

 When the sepals are separate to the very point of 

 insertion the flower is csXl&A. polysepalous. 



The expanded portion of a petal, or that which 

 answers to' the blade of a leaf, is called lamina or 

 blade ; that which answers to the petiole of a leaf, 

 or filament of a stamen, is called claw or unguis. 

 When this claw is absent, we may say that the pet- 

 al is sessile. 



The lower part of a gamopetalous corolla is called 

 a tube^ if the sides are nearly parallel or at least 

 not too spreading. For example, the lower part of 

 the morning glory blossom is a tube. 



