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TEXTBOOK OF BOTANY 



few months. Tulip, hyacinth, and narcissus bulbs that are to be "forced" 

 into early blooming are planted out-of-doors; after several weeks of 

 winter temperatures they are brought indoors. Without this low-tempera- 

 ture treatment of the bulbs, the new plants will develop poorly and bear 

 malformed flowers or none. Inquiry among local nurserymen will prob- 

 ably disclose other practical problems connected with the winter season. 



Fig. 22. Springtime: Winter dormancy is broken and the beech leaves are 



unfolding. 



Spring aspect. The lengthening of the daylight period and increase in 

 temperature bring to an end the dormant period of plants. Lawns and 

 fields begin to green through renewed growth of dormant leaves and 

 buds. Buds on many trees and shrubs enlarge and a new set of twigs 

 and leaves develops (Fig. 22). This is the best time of year to see that 

 the buds of woody plants are stem tips bearing either leaves or rudi- 

 mentary flowers, or both, usually with an outer covering of scales. Exami- 

 nation of trees and shrubs at this time will disclose not only these three 

 types of buds, but also several ways in which buds "open" and enlarge. 

 This is the time of year when you can learn by your own observations: 



