324 FLOWERS 



D. ii. Give examples of variations of the androecium. 



E. 12. Define pistil. 13. Distinguish between simple and com- 

 pound pistils, and define placenta. 14. Define hypogyny, perigyny, 

 and epigyny, giving examples. 



F. 15. Are the most complex flowers the most advanced in evolu- 

 tion? Explain your answer. 16. Discuss floral numbers. 



G. 17. State four fundamental differences between monocotyle- 

 dons and dicotyledons. 



Section 63. A. 1. Define inflorescences and discuss their ad- 

 vantages. 2. Give examples of Composite other than those in the 

 book, and explain why the family is so called. 



B. 3. Distinguish between determinate and indeterminate in- 

 florescences. 4. Define bract, involucre, pedicel, and peduncle. 

 5. Name seven kinds of determinate inflorescences and give examples 

 of each. 6. Explain and illustrate what is meant by a cyme. 



Section 64. A. 1. Discuss "waste" of pollen. 



B. 2. Mention seven different means by which pollination is 

 accomplished, indicating which of these are more common. 3. Define 

 autogamy, geitonogamy, and xenogamy, indicating which two of 

 these are most nearly alike. 4. Explain the crossing of species, defin- 

 ing species and hybrids. 



C. 5. Define and describe stigmas. 6. Discuss the response of 

 pollen tubes to stigmas. 



D. 7. Discuss the structures that appear to be related to wind- 

 pollination. 8. Why is close-pollination impossible for diclinous 

 flowers? 9. Describe ways in which wind-pollination is compelled 

 to be xenogamic. 10. Describe the flowers of wind-pollinated plants 

 and illustrate by examples. 



E. 11. Discuss the causes of the visits of insects to flowers. 



12. What kinds of insect visitors are of chief importance to flowers? 



13. Define nectary, spur, and pollen basket. 14. Give examples of 

 apparent correlation between insect forms and flower forms. 15. De- 

 scribe the relationship between yucca and pronuba. 16. Discuss the 

 case of the fig and wasp. 



F. 17. Discuss the prevention of close-pollination, defining 

 dichogamy and dimorphism. G. 18. Explain what cleistogamy is, 

 giving examples. H. 19. Compare close- and cross-pollination as to 

 advantages and disadvantages. 



