TRILLIUM l8l 



many petals? Are they opposite or alternate 

 with the sepals? Record their color in fresh 

 (not preserved) specimens. Describe a petal 

 as you did the leaf and sepal. 



(c) With the corolla, a circle of three microsporo- 

 phylls (stamens) each opposite a sepal. By 

 carefully bending back (but not removing) 

 the sepals and petals, observe whether or not 

 the other stamens are in the same circle as 

 the first ones, or in an inner (higher) circle. 

 Describe their location with reference to the 

 petals. Record the total number of stamens. 

 Note that each stamen is composed of: 



(1) A stalk (filament), bearing at its tip, 



(2) An anther, composed of marginal, linear 

 pollen-sacs (microsporangia), and connect- 

 ing tissue (the connective). Observe 

 whether the connective is prolonged be- 

 yond the sporangia. Note that the pollen- 

 sacs dehisce (open) on the inside (i.e. y are 

 introrse). Describe their manner of de- 

 hiscence. 



(3) What do the pollen-sacs contain? De- 

 scribe its color. 



(d) The central pistil composed of: 



(1) The basal ovule case (ovary) . How many 

 angles has it? How many lobes? 



(2) The relatively long styles. How many? 

 Their inner surface is modified into 



(3) A stigma. Describe this stigmatic surface 

 as seen both with unaided eye, and under 

 the low power. Usually numerous pollen- 

 grains may be seen adhering to it. What 

 process has therefore taken place? 



