512 PART IV. CLASSIFICATION. 



In all cases the structure of the gynseceum is variable : it is 

 frequently oligomerous. 



The sub-divisions in which the Dicotyledons are arranged in the 

 following classification are especially characterized by peculiarities 

 in the structure of the flower. It is impossible, however, to draw 

 sharp distinctions between the sub-classes, the cohorts, the orders, 

 and sometimes even between the families, for the position of a 

 plant in the system depends, not upon any one character, but upon 

 the aggregate of its characters. 



The principal orders of Dicotyledons may be arranged as 

 follows : 



SUB-CLASS I. MONOCHLAMYDE^E. 



Cohort I. Urticales. Cohort III. Chenopodiales. 



Order 1. URTICACE^E. Order 1. CHEXOPODIACE^. 



2. HORACES. 2. POLYGONACPLE. 



3. CANNABINACE.E. Cohort IV. Asarales. 



,, 4. ULMACE^E. Order 1. ARISTOLOCHIACE^. 



Cohort II. Amentales. Cohort V. Santalales. 



Order 1. BETULACE^E. Order 1. SAXTALACE.E. 



2. CORYLACE.E. 2. LORAXTHACE.E. 



3. FAGACE/E. Cohort VI. Euphorbiales. 



4. JUGLAXDACE.E. Order 1. EUPHORBIACE.E. 

 5. SALICACEJE. 



SUB-CLASS II. POLYPETAL.E. 

 SEEIES I. THALAMIFLOJELE. 



Cohort I. Ranales. Cohort III. Parietales. 



Order 1. RAXUXCULACE^E. Order 1. PAPAVERACE.E. 



2. MAGNOLIACELE. 2. FUMARIACE.E. 



3. NYMPHJEACE^E. 3. CRUCIFER.E. 



4. BERBERIDACE.E. 4. CISTACE^:. 



Cohort II. Caryophy Hales. 5. VIOLACE^:. 



Order 1. CARYOPHYLLACEJE. Cohort IV. Guttiferales. 



Order 1. HYPERICACK<. 

 Cohort V. Malvales. 

 Order 1. TILIACE^:. 

 2. MALVACEAE. 



