THE FLOWER 



113 



158. The top-shaped recep- 

 tacle of Nehinibo, 

 the "Water Chinque- 

 pin, ripening into a 

 float for the dissemi- 

 nation of the seeds. 



which all the organs of each kind are separate from one 



another ; and each set comprises a 



small number, as three or five. In 



such a case ^ it is the rule to find 



the organs in whorls,^ and the whorls 



arranged so that the organs of one 



whorl stand above the spaces of 



the whorl below, just as is the case 



with whorled foliage leaves. The 



petals thus stand over the spaces 



between the sepals, the first row 



of stamens alternates with the 



petals, the second row of stamens 



(if present) with the first, and the pistils alternate with 



the stamens. When the various members of the flower 



are more numerous and the receptacle somewhat elon- 

 gated, as in the Magnolia, the parts are spirally placed. 



In short, the organs of the flower are arranged like 



leaves. 



218. Morphology of the floral parts. — Sepals and petals 



are evident leaves, as they are commonly and properly 



called. There are numerous 

 cases where green forms, func- 

 tioning as foliage, pass over 

 by easy gradations to the 

 white or bright-colored forms 

 subserving the purposes of 

 the flower. In shape, in fun- 

 damental structure (in pos- 

 sessing veins, etc.), and in 

 arrangement on the axis, the 

 parts of the perianth show 

 the morphology of leaves. 

 Stamens and pistils, also, agree 



with leaves in the order of insertion on the axis, as well 



159. Transition from green outer 

 floral leaves (sepals) , through 

 petals, to stamens, in Water 

 Lily ; indicating the unity of 

 nature of sepals, petals, and 

 stamens. 



1 Sometimes called a pattern flower. 



2 A whorl is a circular group of several organs standing at the same 

 level on the axis. 



OUT. or BOX. — 8 



