XXX 



BOTANY. 



longer than the other two, the androecium is said to be didyna- 

 mous (Fig. XXIV) ; 



Pentandrous, of five stamens ; 



Memndrous, of six stamens ; when four are longer than the re- 

 maining two, the androecium is said to be tetradynamous. (Fig. 

 XXV.) 



Other terms of similar construction are used, as heptandrom, 

 seven stamens; octandrous, eight; enneandrom, nine; decandrous, 

 ten; dodeeandrous, twelve; a,Dd polyandrous, many or an indefinite 

 number of stamens. 



Fio. XXXV. 



FiO. 23T. 



Fia XrVI. 



Fig. XXrV.— Tetrandrous flower; stamens didynamous. 

 Fig. XXV.— Hexandrous flower; stamens tetradynamous. 

 Fio. XXVI. — Bicyolic androecium. 



The stamens may be in a single whorl (monocyclic), in which 

 case, if agreeing in number with the rest of the flower, the an- 

 dioscium is said to be isostemonous ; they are often in two whorls 

 Cpicyclic, Fig. XXVI), and when each whorl agrees with the 

 numerical plan of the flower, the andrcecium is diplostemonous. 



Union of Stamens. — The various kinds of union require the use 

 of special terms. "When there is a union of the filaments the an- 

 droecium is 



Monadel/plious, when the stamens are united into one set (Fig. 

 XXVII); 



Diadelphous, when united into two sets (Fig. XXVIII) ; 



Triadelphous, when united into three sets, etc. (Fig. XXIX) 



"When there is a union of the anthers the androecium is syngene- 

 Bious or synantherous. 



Adnation of Stamens.— The stamens may be adnate to the petals, 

 ■when they are epipetalom; in some cases they are iidnate to the 



