LESSON 32.] THE MORNING-GLORY. 191 



its composition. But the five leaves of the calyx would lead him to 

 expect a corolla of five parts also. And, although there are here 

 really no lobes or notches to be seen, yet the five plaits of the corolla 

 answer to the notches, and prove it to consist of five petals perfectly 

 united. Since the stamens are of the same number as the plaits 

 of the corolla, and are placed before them (as may be best seen by 

 splitting down the corolla on one side and spreading it out flat), it 

 follows that they alternate with the lobes, or petals ; therefore our 

 plant belongs to the subdivision C. 



555. Next, the ovary is free from the calyx ; so the plant falls 

 under the section * * , at the top of page xxi ; and the regular 

 flowers and the number of stamens bring it under the subdivision 

 +- H . Then our choice out of the five equivalent lines beginning 

 with "Ovary" or "Ovaries" falls upon the third, viz. "Ovary 2- 

 10-celled," ours being two-celled. Our plant has a style, and green 

 herbage, referring it to the second of the next alternatives. Its 



O * O 



five stamens borne on the corolki bring it to the third of the next 

 set of lines ; and the absence of stipules, to the second line of the next 

 alternative ; and, finally, its alternate leaves and only four-seeded pod 

 bring us to the name of its order, viz. CONVOLVULACE^E, p. 332. 



556. Then, by the synopsis of that order, we refer the plant to the 

 tribe CONVOLVULE^E, to the section with one star, and the sub- 

 section H \ (the calyx being surrounded by two broad leafy bracts), 

 and so to the genus, 4. CALYSTEGIA; and under that genus (p. 334) 

 we are led to the species SEPIUM ; CALYSTEGIA SEPIUM (or Hedge 

 Bindweed] being the name of our plant. 



LESSON XXXII. 



HOW TO STUDY PLANTS I FURTHER ILLUSTRATIONS. 



557. THE foregoing illustrations have all been of the first or Exo- 

 genous class. We will take one from the other class. 



558. A striking and rather common plant of our woods in spring 

 is the Three-leaved Nightshade, or Birthroot. With specimens of 

 this in hand, and the Manual before him opeai at the Artificial Key, 



