TRILLIUM SP. 147 



V. THE LEAVES. 



1. The scale-leaves of the root-stalk. 



a. The bases of decayed scales at each node. 



b. Younger ones sheathing the apex of the root-stalk, 

 the bud, and base of the aerial branch. 



2. The foliage leaves. 



a. Their number, arrangement, and shape. 



b. The outline of the base, margin, and apex. 



c. The leaf-stalk or petiole (not present in all species). 



d. The system of veining. 



3. Draw different forms of scales and one foliage leaf. 



VI. THE FLOWER. Observe: 

 i. The parts of the flower. 



a. The lower cycle of green leaves, the calyx, each mem- 

 ber of which is a sepal. 



b. The cycle of colored leaves above the calyx, the corolla, 

 each member of which is a petal. 



c. The two cycles of organs next above the corolla, each 

 member of which is a microsporophyll or stamen. In 

 one stamen observe: 



i. The stalked base, the filament. 

 ii. The enlarged tip, the anther, showing on its inner 

 face four swellings, the microsporangia. In an- 

 thers that have opened, masses of microspores 

 (pollen-grains) may usually be seen. 



d. The innermost organ of the flower, made up of three 

 megasporophylls or carpels united into one pistil. 

 Each pistil is composed of: 



i. An enlarged base, the ovary, in which megasporan- 

 gia or ovules are formed. Tear open the ovary and 

 locate the ovules. 



ii. A short tapering portion immediately above the 

 ovary, the style. 



