Trees ok the Northern United States 3o 



:,. DICOTYLAE. 



I'crinatli noii..' or (.1 similar segments or divided into 

 calyx and corolla; corolla when present chori- 

 petalous (petals distinct), sepals, petals and stamens 

 sometimes on a disk or hypantbium. G. 



i*crinalli comijosed of calyx and corolla, calyx may be 

 niinntc or sn])prcssed; corolla sympetalous (petals 

 more or Ics> nnited). -V-K 



Calyx and corolla l)otli i)rcsciit. calyx may be mintitc. 

 I . 



Only the calyx i)rcsent, sepals distinct or nnited. 

 .s^n-een or colored; or perianth none. 25. 



h'lowers hypogynous or perigynous; ovulary free or 

 only slightly adherent to the perigynous disk or 

 hypanthinm. 8. 



Flowers epigynons or apparently epigynous; calyx 

 above the ovulary, with or without an hypan- 

 thinm. 24. 



Stamens numerous, at least more than 10 and more 

 than twice the petals. 9. 



Stamens not more than twice as many as the petals, 

 when of just the number as the petals then alter- 

 nate with them. 12. 



Stamens of the same number as the petals and op- 

 posite them; ovulary 2-5-locular, calyx 4-5-cleft. 

 valvate in llie bud; iietals involute; fruit a drupe 

 or capsule; shrubs, small trees, or vines with sim- 

 ple leaves. Rh.nmn.xce.xk. 



a. Rhamnus, CM). 

 Carpels 1 or more, united, but >lyle> and stigmas 



may be several. 1<». 

 Carpels more than 1. district; hlamcnts shorter than 



the anthers; i)erianth trimerous; leaves 2-raid<ed. 



Anonaceae, 



a. Asimina. (14). 

 Carpels numerous spirally .irvanged and cohering 

 over each other. formiuL; an aggregate cone-like 

 fruit; trees; >epals and petals in threes ; twigs 

 with stifynlar ring>. M AfiNoi.iACKAi;. 



