INFLORESCENCE. 



77 



Bracts (7>, 6, b). Fig. 237. Cornus Canadensis, with an involucre of four colored 

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

 239. Calla palustris, with a colored spathe of one bract, inclosing the spadix. 



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

 differing only in their diminished size, and in their position 

 on the flower-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 of the cluster of flowers, an involucre is formed, such as 

 we find in Carrot, and most of the Umbel worts (Fig. 244). 

 In the Flowering Dogwood the large involucre is colored 

 white. 



148. Next in resemblance to the s^ike 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 spathe] at base, 

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



147. What sort of leaves grow on the peduncles, if any ? Define bracts 

 What is an involucre? How is it iu Cornus? 



