48 FAMILIAR LESSONS IN BOTANY. 



The larkspur, violet, columbine, monk's hood, horned 

 poppy, etc., present us with a variety of nectaries in the 

 form of hoods, spurs, horns, scales, cavities, etc. 



107. A little more talk about the corolla, and we are 

 done. Some flowers have stamens and pistils, but no calyx 

 or corolla. Sometimes they have the two latter and only 

 stamens, and again no stamens, only pistils. However, if 

 the stamens and pistils are present it is said to be Vi])erfect 

 floiuer, as they alone are indispensable for the reproduc- 

 tion of the plant. If all the organs are present we say it is 

 entire. When the calyx and corolla are absent, the flower 

 is said to be aclilamydeous (from the Greek, signifying 

 without a cloak) ; when only the calyx is present, mono- 

 chlamydeous (one garment or covering) ; dichlamydeous 

 (two) when the two floral envelopes are present. In this 

 case we say it has calyx and corolla. The Crinum Ameri- 

 canum, found upon Buffalo Bayou, near Houston, and in 

 some parts of Louisiana, familiar to you aW, is monocJilamy' 

 deoics J also the common white lily. The rose is dichlamy- 

 deous. The sweet gum (liquid amber) is aclilamydeous, 



108. The most important office of the corolla seems to 

 be the protection of the stamens and pistils from injury. 

 We thus frequently find the corolla using the greatest care 

 to insure this. Many of them close up at night, or at the 

 approach of rain-storms and high winds; others droop 

 their heads at evening, evidently to prevent too great an 

 accumulation of dew in their cups at night. When you 

 learn the important office of the stamen and pistil, you 

 will more readily perceive the necessity of this protecting 

 care. It is the corolla that also elaborates the volatile oils 

 that give such delicious fragrance to the flower, making 



1 07. Have all flowers a calyx and corolla ? Have all pistils? Stamens ? When 

 is a, Aovfer perfect ? Entire? Achlamydeous? Monochlamydeous ? Dichlamy- 

 deous ? Examples ? 



108. What is the most apparent use of the corolla? Mention the coverings 

 with which it protects the other organs. What is elaborated by the corolla ? What 

 of poisonous plants ? 



