Arrangement of Floral Leaves in the Bud. 



83 



three ways shown in Fig. 62. When the edge3 meet with- 

 out overlapping they are said to be valvale; when one edge 

 is in and the other out all the way around, giving a twisted 

 appearance, they are convolute; and when they overlie each 

 other like the leaves of a cabbage head, they are imbricate. 

 Petals are sometimes crumpled in the bud as in the true 

 poppies. In morning-glories and some other flowers which 

 have the petals united so as to form an entire or nearly 

 entire limb the corolla is plaited in five folds which overlap 

 each other convolutely. In pea blossoms, as we have ob- 

 served, the lower pair of petals 

 cohere along one edge forming a 

 sheath which encloses the stamens 

 and pistil. These in turn are 

 covered by the side petals and the 

 whole is enfolded by the upper 

 petal. In many irregular flowers 

 the three lower lobes fold up over 

 the upper pair. Filaments and 

 styles are sometimes doubled or 

 coiled in the bud, as in eucalyptus 

 and four-o'clock. 



Make cross-sections of your 

 buds and draw diagrams to show the arrangement of the 

 parts. As a map shows better than a picture the relative 

 positions of features in a landscape, so a diagram of a bud 

 or flower shows more clearly its plan than a picture or 

 even an accurate drawing of a section. A careful study 



Fig. 62. Floral leaves in the bud. 

 a. Young bud of lavatera with val- 

 vate sepals enclosing the rest of the 

 flower, b. An older bud of the same, 

 the convolute petals ready to open. 



