THE INFLORESCENCE. 



109 



in like manner on either side, and opposite to each other, b 2, and which differ froia 

 the outer ones in that they hear 

 the organs of fructification, and 

 each one, in fact, is a separate 

 flower. These have heen known 

 as the Gluma interior, or more 

 recently as the/wfesor chaff. With- 

 in each of these is a third structure 

 consisting of two minute and some- 

 what fleshy scales, d, to which 

 the term glumetta or squamul has 

 been given. Of these thiee struc- 

 tures it is prohable that the first 

 >r the external glumes have the 

 greatest analogy to bracts. 



The Cupule or cup, as in the 

 hazel-nut (Corylus), and acorn 

 (Quercus), is another instance in 

 which the bracts constitute the 

 covering of the flower. 



The Spathe is a large bract 

 coloured on its inner side, as in 

 the common Arum, and in palms, 

 and in the numerous plants ar- 

 ranged with them. In this in- 



stance there is much evidence 



Fig. 200. The arrangement of the flowers in Grasses. 



that the inner coverings of the a. A series of flowers arranged on a rachis or stalk. 



flnwpr p-n'<!t hut orA indJaQnliihlir b ' A smaller portion magnified, 

 flower exist, but are mdissolubly ^ The empty external glume . 



Connected with the bract. 2, The internal glume with the organs of fructification. 



In the amt^tt^ or compound 

 flowers, as the rosemary, there are 

 many rows of bracts around each head of flowers on its external surface. This 

 is called the common involucre ; but besides these there are other bracts placed upon the 

 head between the little florets, and from their resemblance to chaff they are called palece. 

 In the sedge tribe (carex) each floret has two bracts adherent at the edges named 

 urccolus, or perigynium. 



The term involucre is employed whenever a series of bracts surrounds a number of 

 flowers. The word universal is also added in the umbelliferous plants, as the carraway 

 seed (Carum Carui), to distinguish the common involucre of the whole head of flowers, 

 whilst the term partial designates the involucre of each little division of the flowers 

 (umkelltttet). 



Perianth (Fig. 201) is a term employed to designate such flowers as have the two 

 next coverings, the calyx and corolla, combined. Such is the flower of the tulip and 

 the orchis. In many instances the inner divisions of the perianth are more gaudily 

 coloured than the outer ones, thus indicating the separation into corolla and calyx 

 which naturally occurs, and it is customary to describe the three outer leaves of the 

 perianth as a calyx, and the three inner as a corolla. 



The Calyx is that covering of the flower which externally is enclosed by the bracts, 



