CYME. 105 



rays answering to petals, and the involucre (254) to the calyx. The flowei-s are 

 called florets, those in the outer circle, florets of the ray, and those of the central 

 portions, florets of the disk. 



304. The panicle is a compound inflorescence, formed by an 

 irregular branching of the pedicels of the raceme. Ex. oats, 

 Poa, and many other grasses. 



305. The thyrse is the same as the panicle, having the 

 lower branches rather shorter than those in the midst, and all of 

 them very compact, as in the lilac (Syringa), horse-chestnut. 



a. The umbel becomes compound when each pedicel becomes 

 itself an umbel, as in most of the Umbelliferse. Li these cases 

 the secondary umbels are called umbellets, and sometimes 

 partial umbels. See ^ 254. 



By a similar decomposition, a raceme becomes a compound 

 raceme, a corymb a compound corymb, &c. 



FIG. 38. — Modes of inflorescence ; 1, raceme ; 2, ament ; 3, spadix ; 4, head ; 5, panicle ; 

 6, veiticillaster ; 7, thyrse. 



306. Of the centrifugal inflorescence, the following varieties 

 are described ; namely, c/j'HTie, fascicle, and verticillaster. 



307. Cyivie. This inflorescence has the general aspect of the 

 corymb, but is remarkably distinguished from it by its centrifu- 

 gal evolution, and by its branches being repeatedly 2-forked 

 and 3 -forked, as exemplified in Hydrangea, Viburnum, chick- 

 weed. 



a. The cj-me is found only in plants with opposite leaves, and its normal struc- 

 ture and development are as follows. The terminal flower, which is the first to 



