xxvi BOTANY. 



flowers); in some cases they are arranged in spirals, with, how- 

 ever, a distinct separation of the difEerent groups of organs 

 Qiemieydic flowers) ; in still other cases the 

 arrangement is spiral throughout, with no 

 separation of the groups of organs {acydie 

 flowers). 



In cyclic flowers there are most frequently 

 four or five whorls, viz. (Fig. XXI) : 



1. The Galyx, composed of (mostly) green 



The Corolla, composed of (mostly) col- 

 ored petals. The calyx and corolla may be 

 spoken of collectively as the Perianth. 

 This term is also used when but one whorl 

 of floral leaves, or a portion of it only, is 

 present. 



3. (4.) The Andrcecium, composed of one 



Fig. XXI.-Diagram to *"■ *^° ^^°''^® °^ stamms. 



show the four floral 4 Or 5. The GynouAv/m, composed of the 



whorls; the lowermost . ..^ . ,.7 



the sepals, composing the piStll or pistils. 



^^I^JL*S.t°?ti"'!.?®'S'*' These whorls usually contain definite 

 composing the corolla; •' 



the next the stamens,com- numbers of organs in each: in many cases 

 posing the andrcecium; ., , ., ^ n ii 1 1 



the uppermost the pistils, the numbers are the same for all the whorls 

 composing the gynoecium. (,f ,1^ flower {isomerous flower); when the 

 numbers are different the flower is said to be Jieteromeroits. 



The terms which denote these numerical relations are : monocyclic, 

 applied to a flower having only one cycle; Hcyclie, two cycles; 

 tricyclic, three cycles ; tetracyclic, four cycles •,psntaeyclie, five cycles, 

 etc. ; monomerous, applied to flowers each cycle of which con- 

 tains one member; dimerous, two members; trimerous, three 

 members; tetramerous, four members; pentameroits, five mem- 

 bers, etc. etc. 



Floral Formulae. — These relations can be briefly indicated by 

 using symbols and constructing floral formulae, as follows: 

 Ca6, Coe, Aub, Gub = a tetracyclic pentamerous flower; 

 Cas, Cos, Ana + 3, Guj = a pentacyclic trimerous flower. 



Most commonly the members of one whorl alternate with those 

 of the whorls next above and below; in a few cases, however, they 

 are opposite (or superposed) to each other. 



Floral Diagrams. — These relations may be indicated by a mod' 



