IKPLORESCBNCB. 



77 



Bracts (b, b, b). Fig. 237. Cornus Canadensis, with an involucre of four colored 

 bracts. Fig. 238. Hepatioa triloba, with an involucre of three green bracts. Fiff, 

 289. Calla palnstris, with a colored spathe of one bract, inclosing the spadix. 



147. tracts are evidently of the same nature as leaves, 

 differing only in their diminished size, and in their position 

 on thQ fllower-stalks, or near the flowers. They are some- 

 times colored as brightly as flowers, as in Painted-cup, or in 

 Balm. When several bracts are arranged in a whorl at the 

 base 9f the cluster of flowers, a.n-involucre is formed, such as 

 we find in Carrot, and most of the Umbelworts (Fig. 244:). 

 In the Flowering Dogwood the large involucre is colored 

 white. 



148. Next in resemblance to the spike is the spadix, an 

 inflorescence seen in the Calla (Fig. 237), Golden-club (Fig. 

 241), and Cat-tail. It may be defined as a thickened, club- 

 shaped spike, often with a large bract (called spatke) at base, 

 as in Jack-in-the-pulpit, or without a spathe, as in Fig. 241. 



147. What sort of lea-?es grow on the pedimcles, if any 1 Define bracts. 

 ■yVTiat is an involucre ? How is it in Cornus ? 



