56 



PART I. ORGANOGRAPHY. 



large bract called a spathe, which springs from its base. The 

 inflorescence of the common Calla, the Skunk-cabbage and the 

 Indian-turnip, Fig. 185, are illustrations. 



Several of the forms above described 

 may be more or less compounded. For 

 example, there are compound racemes, com- 

 pound corymbs, compound umbels, and com- 

 pound or panicled spikes. The compound 

 raceme, particularly if it is somewhat 

 irregularly compounded, is commonly 

 called a panicle, as in the Yucca, Fig. 186. 

 Fig. 187 illustrates the compound umbel 

 of Fennel, and Fig. 188, the panicled spike- 

 lets of the Oat. 



The bracts which subtend the heads of 

 the Composite, and those which occur in 

 whoi Is at the base of other compact flower- 

 clusters, as the umbels of many Umbelli- 

 ferae, as well as the whorl of bracts which 

 sometimes occurs beneath a single flower, as in the Anemone, 



are termed the involucre. See Fig. 183. 

 A Determinate Anthotaxy is one in 



which the first flower that opens is the 



Fig. 185. — Spadix of In- 

 dian-turnip. 



Fig. 186. — Panicle of Yucca. 



Fig. 187. — Compound umbel of Fennel. 



terminal one on the rachis, and the others appear in succession 

 from the apex toward the base. In case the cluster on this plan 



