v III) FLOWERS OF NEW YORK 23 



varies in different flowers. When the calyx or corolla is divided almost to 

 tlu- base it is said to be parted (figure 63) ; when divided to about the middle 

 it is said to be cleft (figure 64) ; when still less separated it may be said to 

 be lobed or toothed (figure 65) ; or if entire on the margin it is said to be 

 entire (figure 62). 



When the parts of each set of organs of a flower are alike or equal in 

 size, the flower is said to be regular, which means that the petals are alike. 

 the sepals are alike and the stamens are alike. A symmetrical flower is 

 one in which the sepals, petals and stamens are of the same number; 

 unsymmetrical when there are unequal numbers in each cycle, that is, 

 an unequal number of sepals, petals of stamens. 



Certain groups of plants may often be recognized by the form of the 

 corolla of some of its members. This character seems to be quite constant 

 and the names of several large or important families of flowering plants 

 are derived from this source. Of these groups we may mention the 

 cruciferous (figure 60) type of flower of the Mustard family (Cruciferae), 

 in which there are four spreading petals forming a cross, as in the flower 

 of the Spring Cress (Cardamine bulbosa); the labiate corolla 

 (figure 66) of the Mint family (Labiatae) in which the corolla is more or 

 less two-lipped; the papilionaceous type of flower (figure 61) of the Pea 

 family (Leguminosae), in which the petals are characteristically groujx-d 

 into two lateral (wing) petals, a single upper (banner) petal and a pair of 

 lower petals, often more or less united to form the keel. 



Stamens: 



The general characteristics of the stamens have already been described. 

 In the stamens, as in the case of the petals and sepals, the number and 

 arrangement are subject to great variation in different kinds of plants. 

 Monandrous refers to a flower with a single or solitary stamen ; polyandrous 

 to a flower containing several stamens. The stamens may be monodelphous, 

 in which the filaments are united into a tube, as in the Wild Lupine (figure 

 67), or the stamens may be diadelphous (figure 68), which means two sets 



