LESSON 11.] SORTS OF FLOWER-CLUSTERS. 83 



leaves or bracts about their middle, have branched again, and pro- 

 duced the branchlets and flowers c c, on each side. It is the con- 

 tinued repetition of this which forms the full or compound cyme, 

 such as that of the Laurustinus, Hobblebush, Dogwood, and Hy- 

 drangea (Fig. 167). 



218. A Fascicle, like that of the Sweet- William and Lychnis of 

 the gardens, is only a cyme with the flowers much crowded, as it 

 were, into a bundle. 



219. A Glomerule is a cyme still more compacted, so as to form a 

 sort of head. It may be known from a true head by the flowers 

 not expanding centripetally, that is, not from the circumference to- 

 wards the centre, or from the bottom to the top. 



220. The illustrations of determinate or cymose inflorescence have 

 been taken from plants with opposite leaves, which give rise to the 

 most regular cymes. But the Rose, Cinquefoil, Buttercup, and the 

 like, with alternate leaves, furnish equally good examples of this 

 class of flower-clusters. 



221. It may be useful to the student to exhibit the principal sorts 

 of inflorescence in one view, in the manner of the following 



Analysis of Flower-Clusters, 



I. INDETERMINATE OR CENTRIPETAL. (198.) 

 Simple ; and with the 



Flowers borne on pedicels, 



Along the sides of a lengthened axis, RACEME, 201- 



Along a short axis ; lower pedicels lengthened, CORYMB, 203- 



Clustered on an extremely short axis, UMBEL, 205. 

 Flowers sessile, without pedicels (206), 



Along an elongated axis, SPIKE, 207. 



On a very short axis, HEAD, 208. 



with their varieties, the SPADIX, 209, and CATKIN, 210. 



Branching irregularly, PANICLE, 213. 



with its variety, the THYRSUS, 214. 



II. DETERMINATE OR CENTRIFUGAL. (215.) 



Open, mostly flat-topped or convex, CYME, 216. 



Contracted into a bundle, FASCICLE, 218. 



Contracted into a sort of head, GLOMERULE, 219. 



222. The numbers refer to the paragraphs of this Lesson. The 

 various sorts run together by endless gradations in different plants. 

 The botanist merely designates the leading kinds by particular 

 names. Even the two classes of inflorescence are often found com- 

 bined in the same plant. For instance, in the whole Mint Family 



