30 



KLKMKNTS OF HOT A NY. 



xnons, nr<l ono 5-rollo(l ovnry ; or a 4-niov()UH flower with two sopalH, 

 four potalH, Hixtcc'ii to twouty-four BtaineiiH, ami a l-cellcd ovary. In fact, 

 in oxopfenouH 2)lants tbo numerical arran-jfenient, though commonly in Iivch 

 or fours, proHcnts almost innumerablo exceptions — some, indeed, in whicli 

 the exact plan is scarcely dis(!ernil)le ; hut, he it rcniend)ere(l, it is never 

 eonipl(4cly in threes. In (^ndoij^eiKHis planis, li()W(^ver, Ihe arran<jemejit by 

 threes is much more uniform and the excej)ti()ns niU(!h more rare. 



Fio. 05. — A 111 WIT of tlio coniinon lilac — 

 4-nicrous. 



Fin. r(J. — rivo-mcrouB flower of a geranium. 



Wo have seen that Iho ealyx and corolla may 1)C rej^ular or irregular, 

 and that hoth stanuiiis and pistils are subject to variations also. Another 

 form of irregularity recjuires attention. 



In many plants there is an imperfection in the flowers, some of them 

 being without stamens, others without pistils. These imperfect flowers 

 may be npon the sanui plant, or upon difterent individuals of the same 

 species (Figs. 4G and 47). The common ailanthus, so largely used as a 



PiQ. 67.— riMil (if thfiv. .ith hypocynouB 

 gtnmoiiB. Tho ciuollii and culyx (also hypogy- 

 Douh; romovcd. Kiilnrgrd. 



Fio. 68.— Superior ovary of tho poppy. 



shade-tree, has flowers with stamens only (stamwate) on one individual, 

 and those with pistils only (pistillale) on another. Such plants are termed 

 dioecious; while those Avith both kinds upon the same individxial are 

 termed nioncecious. Still others have not only perfect flowers — that is, 

 those with both stamens and pistils — but these imperfect staminate and 

 pistillate flowers also ; such plants are termed polygamous. 



