260 EXPLANATION OF 



PISTIL ; part of a flower ; composed of the Germen, 

 Style, and Summit. [Plate 1.] 



PITH ; a soft spongy substance, which occupies the 

 middle, or clothes the inner surface of the hollow 

 trunk in some plants ; as in the Rush and Elder. 



PLU'MULA ; the plume, or ascending part, of the cor- 

 culum or heart of the seed. 



POD : a seed-vessel, composed of two yalves or shells ; 

 with a partition, to which the seeds are fixed, al- 

 ternately, to each of the seams or sides. [Plates 1. 

 and 17; and Wood-cut, page 194.] 



POL'LEN, or Fari'na ; a fine powder contained in the 

 anthers of flowers. 



POLYADEL'PHIA ; the name of the eighteenth class : 

 stamens united, by the filaments, in three or more 

 sets. [Plates 2. and 20. ] 



POLYAN'DRIA ; many (more than twenty) stamens. 

 The name of the thirteenth class ; [Plates 2. and 

 15.] in which all the stamens are fixed to the recept- 

 acle. Also the name of an order in the classes 

 Monad elphia,Diadelphia, and Polyadelphia. [Plates 

 18. and 20.] 



POLYGA'MLA ; the name of the twenty-third class, of 

 Linnaeus; three different sorts of flowers on the same, 

 or on separate plants ; some of them containing 

 pistils, some stamens, and others both. [Plate 2.] 



The term is applied also to the subdivisions of the 

 class Syngenesia ; signifying that florets of different 

 kinds are variously combined, and enclosed within 

 one common calyx : the five orders of the class 

 being named as follows, viz. 



