TREES AND SHRUBS. 411 



14. In what way does overwatering affect the health of the 

 cuttings ? 



15. Why does warmth, in most cases, cause starvation of the roots 

 in woody cuttings, while it encourages root growth in herbaceous 

 cuttings ? 



16. Mention some plants which are commonly propagated by (1) 

 cuttings of their roots, (2) isolated pieces of their leaves. 



17. How are the following plants propagated (multiplied) apart 

 from seeds? Dahlia, Rose, Carnation, Aspidistra ("Parlour Palm "), 

 Begonia, Pelargonium (Garden Geranium), Anemone, Lily of the 

 Valley. 



18. In removing a bud from (say) a tuber for purposes of propagation 

 why is it necessary to include in the cutting part of the substance of 

 the tuber itself ? 



19. Draw and describe the appearance during winter of the buds of 

 either Beech, Horse Chestnut, or some other tree. Show by drawings 

 the stages through which these buds pass in spring. How can you 

 hasten the natural opening of a bud on a cut branch ? 



20. Describe the general habit, leaves, and catkins of any kind of 

 Willow (Salix) you know. Make drawings to illustrate the structure 

 of the flowers and explain how pollination occurs. 



21. How can you tell a Poplar from a Willow in winter? 



22. Describe and explain the process of "pollarding" Poplars and 

 Willows. 



23. Which Willows are used for basket-making ? Where do these 

 Willows grow ? 



24. Describe and compare the flowers of Willow and Poplar, giving 

 sketches of their structure. How are the flowers pollinated ? Compare 

 the pollination adaptations of Willows and Poplars. 



25. Describe the winter buds of a Willow or Poplar, with sketches. 



26. How can you distinguish from a distance (a) the Lombardy 

 Poplar, (b) the Aspen? 



27. How could you distinguish an Alder in winter ? Where do 

 Alders usually grow ? 



28. Describe, with sketches, the buds, young twigs, and leaves of 

 Alder. 



29. Describe the male and female catkins and flowers of Alder. Give 

 sketches. At what time of year are the catkins formed ? In what other 

 catkin-bearing trees can both kinds of catkin be seen in winter ? 



