THE SPRING FLORA 181 



have increased in size and what parts have 

 become otherwise changed ? 



(2) Drawings. Draw a transverse and a vertical median 



section of the flower of the apple, magnified 

 sufficiently to show clearly the parts of the ovary 

 and the ovules. 



(3) Discuss briefly the parts of the flower which enter 



into the formation of fruit, and the changes 

 undergone during fruit formation. 



3. Reference readings. Consult various texts concerning the 

 history and reproduction of the cultivated strawberry 

 and apple. Eobbins's " Botany of Crop Plants " is 

 particularly valuable as a reference on the above points. 

 See also Bailey's ''American Horticulture." 



SUPPLE ME NT A R Y STUDY 



1. If time allows, the student should study the flowers and 

 fruits of the wild rose, cherry, raspberry, and blackberry, in order 

 to acquaint himself with the methods of fruit formation in 

 these important fruit-bearing species. 



2. Commercial varieties. Study and record important commer- 

 cial species and varieties of the Rosaceae, as for the Cruciferae 

 and Leguminosae. 



COMPOSITAE 



THE YARROW (ACHILLEA) 



Read the text discussion of the inflorescence, flowers, and 

 fruits of the common yarrow and confirm the points there 

 discussed. 



1. Inflorescence. To what class of inflorescence does that of 

 the yarrow belong ? Bisect the inflorescence vertically 

 and study its parts. What is the form of the axis of 

 inflorescence ? What structures make up the involucre ? 



