THE ARTIFICIAL SYSTEM. 167 



1. THE FIRST THIRTEEN CLASSES comprehend all such plants 

 as have their flowers all perfect, their stamens unconnected and 

 and of equal length, or at least neither didynamous nor tetra- 

 dynamous. 



Class I. MOXAXDRIA, one stamen to each. flower (Saltwort, etc.). 

 Class II. DIANDRIA, two stamens (Circcea, Veronica). 

 Class ILL TRIAXDRIA, three stamens (Iris. Nearly all the Grasses'. 

 Class IT. TETRAXDRIA, four stamens (Galium, Plantago). 

 Class V. PEXTANDRIA, five stamens (Vitis, Conium). 

 Class VI. HEXANDRIA, six stamens (Lily, Tulip, Luzula). 

 Class VII. HEPTAXDRIA, seven stamens (Trientalis). 

 Class VIII. OCTAXDRIA, eight stamens (Erica, (Enothera). 

 Class IX. EXXEANDRIA, nine stamens (Rheum, Sassafras) 

 Class X. DECAXDRIA, ten stamens (Dianthus, Rhododendron). 

 Class XI. DODECANDRIA, twelve to nineteen stamens (Asarum). 

 Class XII. ICOSAXDRIA, twenty or more stamens, perigynous (Rosa). 

 Class XIII. POLYAXDRIA, twenty or more stamens, hypogynous (Ranunculus, 



Papaver). 



2. THE NEXT TWO CLASSES are founded on the relative 

 length of the stamens, the flowers being perfect and stamens 

 generally unconnected. 

 Class XIV. DIDYXAMIA, four stamens, two long and two short, by pairs, as in 



Antirrhinum, Prunella. 

 Class XV. TETRADYXAMIA, six stamens, four long and two short, as in tho 



wall-flower and the Cruciferse generally. 



3. THE NEXT FOUR CLASSES are determined by the con- 

 nection or union of the stamens. 

 Class XVI. MOXADELPHIA, stamens united by their filaments into one set, as 



in Malva, Geranium. 

 Class XVIL DIADELPHIA, stamens united by their filaments into two sets 



(Polygala, pea, Lathyrus).^ 

 Class XVIII. POLYADELPHIA, stamens united by their filaments into three or 



more sets (Hypericum). 

 Class XIX. SYXGEX-ESIA, stamens united by their anthers, as in the Asters and 



other Composite. 



4. THE NEXT CLASS DEPENDS for its character upon the ad- 

 hesion of the stamens with the pistil. 

 Class XX. GYXAXDRIA, stamens and styles united, forming a column, as in 



Orchis, Asclepias. 



5. THE NEXT THREE CLASSES include all plants with diclin- 

 ous flowers, some with pistils, some with stamens only. 

 Class XXI. MOXCECIA, staminate and pistillate flowers, both upon the same 



plant (Pinus, Arum, Hazel). 



Class XXII. DIOECIA, staminate and pistillate flowers on separate plants (Wil- 

 low, Hemp, Hop, Smilax). 

 Class XXIII. POLYGAMIA. staminate, pistillate and perfect flowers either on the 



same or on different plants, as in Acer, Acacia, "Veratrum). 

 6. THE LAST CLASS includes flowerless plants. 



