146 ANTHOTAXY, OR INFLORESCENCE. 



of its axis terminated by a flower (Fig. 281-284) , which answers 

 to a terminal bud. If more flowers appear, so as to compose a 

 cluster, they spring from the axils, preferably from the highest 

 axils, and are later. The order of evolution is shown in the figures 

 by the size of the flower-buds or degree of expansion of the 

 blossoms. Fig. 281 best shows why a determinate or definite in- 

 florescence is sometimes said to be Descending ; Fig. 283 shows 

 why it is called Centrifugal, the central flower first expanding ; 

 Fig. 284 exhibits the lateral or circumferential partial clusters 

 later than the central blossom, and their lateral flowers later 

 than their central. 



271. Varieties of Indeterminate or Botryose Inflorescence. The 

 names of most of these have been fixed from the time of Linnaeus, 

 but defined without reference to the order of evolution of the 

 flowers. They are the Raceme, Corymb, and Umbel, with flowers 

 raised on pedicels ; the Spike and Head, with sessile flowers ; 

 also some modifications of these, notably the Ament and the 

 Spadix. The raceme may be taken as the type. Botrys is 

 equivalent to racemus, &c. ; and, as the type includes diversity 

 of forms to which the name racemose would seem inapplicable, 

 the term botryose (botrytischen of Eichler) is best chosen as the 

 general name of it, and is a good counterpart to cymose for the 

 other type. 



272. A Raceme (illustrated in Fig. 272, 277, and by diagram 

 in Fig. 278) is a simple flower-cluster, in which the flowers, 

 on their own lateral or axillary pedicels and of somewhat equal 

 length, are ai-ranged along a relatively more or less elongated 

 rhachis or axis of inflorescence. The common Barberry, Cur- 

 rant, Choke-Cherry and Black Cherry, and Lily of the Valley 

 are familiar examples. 



273. A Corymb (Fig. 275, 279) is a shorter and broader 

 botr3 r ose cluster, which differs from a raceme only in the relatively 

 shorter rhachis and longer lower pedicels ; the cluster thus be- 

 coming flat-topped or convex. The centripetal character is thus 

 made apparent. The greater number of the corymbs of Linnasus 

 and succeeding botanists are cymes, the central flower first ex- 

 panding. And the term corymbose or corymb-like is still much 

 used in descriptive botany for a ramification which is mainly of 

 the cymose type, and where in strictness the term cymose should 

 be employed. 



274. An Umbel (Fig. 280), as in Asclepias, &c., differs from 

 a corymb only in the extreme abbreviation of the rhachis or axis 

 of inflorescence, and the general equality of the pedicels which 

 thus all appear to originate from the apex of the peduncle, and 



