THE FLOWER 139 



283. When the pieces overlap in the bud, it is in one of two ways ; 

 either every piece has one edge in and one edge out, or some pieces 

 are wholly outside and others wholly inside. In the first case the 

 aestivation is 



Convolute, also named contorted or twisted, as in Fig. 240, a cross 

 section of a corolla very strongly thus convolute or rolled up to- 

 gether. Here one edge of every petal covers the next before it, while 

 its other edge is covered by the next behind it. The other mode 

 is the 



Imbricate, or imbricated, in which the outer parts cover or overlap 

 the inner so as to "break joints," like tiles or shingles on a roof; 

 whence the name (calyx in Fig. 237). 



284. The imbricate and the convolute modes sometimes vary one 

 into the other, especially in the corolla. 



285. In a gamopetalous corolla or gamosepalous calyx, the shape 

 of the tube in the bud may sometimes be noticeable. It may be 



Plicate, or plaited, that is, folded lengthwise; and the plaits may 

 either be turned outward, forming projecting ridges, as in the 

 corolla of Campanula; or turned inward, as in that of Gentian 

 or of Belladonna. 



Position and Arrangement of Flowers, or Inflorescence 



286. Inflorescence, which is the name used by Linnaeus to sig- 

 nify mode of flower arrangement, is of three classes ; namely, inde- 

 terminate, when the flowers are in the axils of the leaves, that is, 

 are from axillary buds ; determinate, when they are from terminal 

 buds, and so terminate a stem or branch ; and mixed, when these two 

 are combined. 



287. Indeterminate, or indefinite, 

 Inflorescence is so named because, as 

 the flowers all come from axillary buds, 

 the terminal bud may keep 011 grow- 

 ing and prolong the stein indefinitely. 

 This is so in Moneywort (Fig. 241). 



288. When flowers thus arise singly from the axils of ordinary 

 leaves, they are axillary and solitary, not collected into flower clusters. 



289. But when several or many flowers are produced near each 

 other, the accompanying leaves are apt to be of smaller size, or of 

 different shape or character: then they are called BRACTS, and the 

 flowers thus brought together form a cluster. The kinds of flower 

 clusters of the indeterminate class have received distinct names, ac- 

 cording to their form and disposition. They are principally raceme, 

 corymb, umbel, spike, head, spadix, catkin, and panicle. 



290. In defining these it will be necessary to use some of the fol- 

 lowing terms of descriptive botany which relate to inflorescence. If a 



