166 LABORATORY AND FIELD EXERCISES 



(2) Floral plan. Are the flowers spiral or cyclic in the 



arrangement of their parts on the receptacle? 

 Are they on the plan of 3, 4, or 5 ? 



(3) Pollination features. Study the adaptations, if any, 



which the flowers possess for securing pollination, 

 as well as the means or agents by which pollina- 

 tion is secured. Be able to designate those of the 

 following terms which apply to the flowers under 

 observation. Are they close-pollinating, cross- 

 pollinating, or self-pollinating ? Have they color, 

 odor, nectar, or any other attractive features for 

 securing insect pollination ; that is, are they ento- 

 mophilous ? Are they adapted for wind pollina- 

 tion ; that is, are they anemophilous ? If so, be 

 able to state the adaptation. 



c. Fruit and seed. Study the nature of the fruit and its 



origin from the pistil. Are there special devices for 

 seed and fruit dissemination ? Do you know of any 

 wild tract which has been seeded by fruits dissemi- 

 nated from near or distant trees of the species you 

 are studying ? In what places in your region are 

 trees most successful in producing offspring by seed 

 dissemination ? In what places in other regions ? 

 Considering the large number of seeds produced by 

 each tree, why are trees not more abundant ? 



d. Drawings. Make sketches to illustrate the structure, 



floral plan, and pollination features of the flower. Draw 

 the fruits and label all parts correctly. These draw- 

 ings can be made separately or with other drawings 

 of the species, as in the poplar, on the Species Record. 

 4. Anatomy. Cut gross transverse sections of twigs or small 



branches. Observe the nature of the wood, phloem, 



and bark. 



