PHANEROGAMIA : FLOWERS. 307 



3. The blooming follows no such simple order; it may com- 

 mence in the centre, and proceed both upwards and downwards 

 simultaneously, as in the capitula of Dipsacus ; or the upper and 

 middle buds may begin to open simultaneously, and the blooming 

 proceed downward in two divisions, as in Campanula Medium. 

 This may be termed indefinite inflorescence (itifl. vaga). 



In compound axes the same condition occurs with respect to 

 main axes and adventitious axes, and is by no means necessarily 

 uniform with the law for the simple axis. Thus, in most Com- 

 positoe the infl. centripeta frequently occurs in the single capitula ; 

 and infl. centrifuga in the side branches, in relation to one another, 

 as occurs in Centaurea calocephala: in Sanguisorba, on the con- 

 trary, the main capitula, as well as the side branches, exhibit infl. 

 centrifuga. The generality of the LabiattB exhibit in the inflo- 

 rescence of the individual side branches, an infl. centrifuga^ whilst 

 the branches themselves are centripetally developed. 



This relation of condition, as is self-evident, is one altogether foreign 

 to the inflorescence, i. e. the arrangement of the flowers, and belongs to 

 the vital phenomena of the plant as a whole ; unfortunately, however, 

 through want of clear logic, it has become entangled in the study of the 

 inflorescence, and I was therefore obliged to refer to it here. Any brain 

 with a little logic in it, will readily see that the course of the unfolding 

 of the flowers does not possess equal importance with the arrangement 

 of the single flowers, in establishing the various kinds of inflorescence ; 

 but at most may subordinately contribute, in one and the same species of 

 inflorescence, specific distinctions for single groups, genera, or species 

 of plants. 



142. Upon the condition of structure we have here little to 

 say, since this subject was necessarily forestalled in the axis and leaf; 

 and here only relations of position alone come into the question. 

 The bracts and bracteoles are commonly formed of thin- walled 

 cellular tissue, delicate, and often coloured * ; sometimes in entire 

 families of plants, they are perfectly dry and sapless. The vascular 

 bundles of the pedicels sometimes stand in definite proportion to 

 the number of the floral leaves. 



REVIEW OF THE INFLORESCENCE IN GENERAL. 



143. A. The solitary flower, as terminal or axillary flower (fos 

 solitarius, term, vel axilT). The latter may be situated in whorls, 

 and then form a verticil (verticillus). 



B. Simple Inflorescence, 

 a. Inflorescentia centripeta. 



1. The capitulum. The undeveloped axis is here usually en- 

 larged upward, with a fleshy or spongy substance, and the more 



* Coloratns, i. e. of some other colour than green. 

 x 2 



