INFLORESCENCE. 



69 



332. THE peduncle is subject to endless modifications. "We find it sometimes 

 excessively lengthened, again very short or wholly wanting ; very slender or very 

 thick. In. cockscomb its branches are blended into a thick, fan-shaped mass; in 

 butcher' s-broom it expands into the form of a green leaf, arid in the linden-tree into 

 a seal-like bract In Xylophylla it is foliaceous, bearing flowers along its margins. 



333. BRACTS. The branches of the inflorescence arise from the 

 axils of reduced leaves, called bracts. These leaves, still smaller, grow- 

 ing upon the pedicels, are called bracteoles. 



334. The bracts are usually simple in outline and smaller than the 

 leaf, often gradually diminishing to mere points, as in Aster, or even 

 totally suppressed, as in the Cruciferse. 



335. IN COLOR they are usually green, often colored, sometimes bril- 

 liantly, as in painted-cup. Sometimes they are scale-like, and again 

 they are evanescent membranes. 



336. THE SPATHE is a large bract formed in some of the monocotyle- 

 dons, enveloping the inflorescence, and often colored as in the Arum, 

 Calla, or membranous as in the onion and daffodil. Bracts also con- 

 stitute an 



191 190 1S9 



Bracts (5, Z, I,}. ISO, Cornus Canadensis, with an involucre of 4 colored bracts. 190, Hepatica 

 triloba,with an involucre of 3 green bracts. 191, Calla palustris, with a colored spathe of one 



bract 



337. INVOLUCRE when they are collected into a whorl or spiral 

 group. In the Phlox, Dodecatheon, and generally, the involucre is 

 green, but sometimes colored and petaloid, as in dogwood and Euphor- 

 ,bia. Situated at the base of a compound umbel, it is called a general 

 involucre, at the base of a partial umbel it is a partial involucre or in- 

 volucel, both of which are seen in the umbelliferse. 



338. IN THE COMPOSITE, where the flowers are crowded upon a com- 

 mon torus, forming what is called a compound flower, an involucre com- 

 posed of many imbricated scales (bracts) surrounds them as a calyx 

 surrounds a simple flower. The chaff also upon the torus are bracts 

 to which each floret is axillary. 



