SPECIAL EXERCISES ON TYPICAL FLOWERS 217 



Suggestion. Find out what use is made of dandelion 

 root (taraxacum). How do gardeners exterminate this 

 weed ? Its use in spring as salad and greens is well known. 



Method (Field). Make observations on a dandelion plant 

 from day to day, taking note of the following points : 



(a) Character of soil where it grows. 



(6) Variation in size and shape of leaf due to habitat. 



(c) Leaf arrangement (rosette) affording large surface in 

 small space. 



(d) Absence or shortness of stem affording protection from 

 browsing animals and from cold weather. 



(e) Effect of the leaf arrangement in monopolizing space 

 to the exclusion of other plants. 



(/) Behavior of the plant, especially the action of the 

 involucres in opening and closing the flower in different 

 stages and under different conditions of light and weather. 



(g) Mark a bud which is about to open by tying a colored 

 thread about its peduncle (flower stalk). Note when it 

 opens and closes, also how many days it continues to open 

 and close. 



(h) When the ball of fruit expands, observe the manner 

 of seed dispersal. 



(i) Carefully dig up a plant and study the long, sturdy 

 taproot. 



There is another group of composite plants whose flowers 

 are all tubular. The commonest ones are ironweed, the 

 thistles, and bonesets. 



Suggestion. Study a plant of burdock or thistle as in 

 the other exercises on composites. Draw a head, showing 

 the outer involucre of hooked or prickly bracts. Cut a 

 head lengthwise and draw the section exposed. Remove 

 a flower and draw it greatly enlarged. 



