STRUCTURE OF FLOWERS. 



67 



the very extremity of the branch that bears it, or laterally, and 

 in this last case, it arises from the axil of a leaf, which on this 

 account has been called floral leaf, when it resembles other 

 leaves (fig. 86), and is named bract (from the Latin, bractea, 

 a thin leaf of metal), when it differs from the other leaves in its 

 colour, its form (figs. 75 and 76), or in the absence alone of the 

 buds in its axil. 



19. These bracts may be found at the base of the peduncle, 

 or at the base of each of its divisions, when this support is 

 ramified as in pedicelate flowers. When they are symmetrically 

 arranged around one or several flowers, so 

 as to form a kind of accessory envelope, 

 the assemblage is called an involucre 

 from the Latin, involutus, folded in (fig. 

 75). Generally, they have a foliaceous 

 consistence, but they sometimes resemble 

 little scales, more or less closely embracing 

 the base of the flower. When the in- 

 volucre surrounds a single flower, and is 

 very close to it, it often resembles one 

 of the proper envelopes of the flower, 

 called calyx (Latin, the cup of a flower), 

 and in this case it is commonly known . _. 

 under the name ofcalicula, as in the mal- 

 low. When the involucre entirely covers a flower before it is 

 blown, and the flower is not seen externally until this envelope 



Fig. 76. SPATHE. 



Fig. 77. GLUME. 



is torn open or unrolled, it is called a spathe (fig. 76, sp, from 

 the Greek, spathe, a ladle) : the common onion, narcissus (fig 



19. What is an involucre ? What is a spathe ? What is a glume ? 



