THE FLOWER 



221 



the young sporophylls, but they are all alike, forming what 

 is called the perianth (Figs. 197, 198). 



In still higher forms the perianth differentiates, the 

 inner floral leaves become more delicate in texture, larger 

 and generally brightly colored (Fig. 199, A). The outer 

 set may remain scale-like, or become like small foliage 

 leaves. When the dif- 

 ferentiation of the peri- 

 anth is distinct, the 

 outer set of floral leaves 

 is called the calyx, each 

 leaf being a sepal; the 

 inner set is the corolla, 

 each leaf being a petal 

 (Fig. 200). Sometimes, 

 as in the lily, all the 

 floral leaves become 

 uniformly large and 

 brightly colored, in 

 which case the term 

 perianth is retained 

 (Fig. 201). In other 

 cases, the calyx may be 

 the large and colored 

 set, but whenever there 

 is a clear distinction 

 between sets, the outer 

 is the calyx,' the inner 

 the corolla. 



Both floral sets may 

 not appear, and it has 

 become the custom to 

 regard the missing set 

 as the corolla, such 

 flowers being called 



apetalous, meaning 

 33 



Fig. 201.— An easter-lily. a Monocotyledon, 

 showing perianth (a), stamens (6). stigma (c), 

 flower bud (d), and a carpel after the peri- 

 anth has fallen (I), with its knob-like stigma, 

 long style, and slender ovary. — Caldwelu 



