X KEY TO THE ORDERS 



Gynoecium 2-4carpellary, the carpels united. 



Oleaceae in Order Gentianales. 245 

 Stamens perigynous or epigynous, inserted on the margin of 

 a hypanthium or a disk. 

 Fruit a samara. Families in Order Sapindales. 201 



Fruit not a samara. 

 Fruit drupe-like or berry-like : shrubs or trees. 



Order Rhamnales. 206 

 Fruit a capsule : herbs. Order Aristolochiales. 112 



dd. Ovary inferior. 



Flowers not in involucrate heads. 

 Fruit a berry or a drupe, or nut-like. 

 Stamens as many as the perianth-members and alternate with 



them, or fewer. Cornaceae in Order Umbellales. 225 



Stamens as many as the perianth-members and opposite them, 

 or twice as many. 

 Styles present. 

 Ovules erect. Order Santalales. hi 



Ovues pendulous. Families in Order MyrtaleS. 220 



Styles wanting : stigmas sessile. 



Haloragidaceae in Order Myrtales. 220 

 Fruit a capsule. 

 Sepals as many as the ovary-cavities or one-half as many. 

 Calyx regular and the sepals half as many as the cavi- 

 ties in the ovary, or irregular. 



Order Aristolochiales. 112 

 Calyx regular and the sepals as manj' as the cavities in the 



ovary. Order INIyrtales. 220 



Sepals (4-5) at least twice as many as the ovary-cavities (2). 



Saxifragaceae in Order Rosales. 157 

 Flowers, at least the staminate, in involucrate heads. 



Ambrosiaceae in Order Campanulales. 298 

 AA. Corolla present, 

 e. Petals distinct, at least at the base. 



Carpels solitary, or several and distinct, or united only at the base. 

 Stamens at the base of the receptacle, i. e., hypogynous. 

 Flowers in monoecious heads. Platanaceae in Order Rosales. 157 

 Flowers not in monoecious heads. 

 Plants with relatively firm stems and leaves, not succulents. 



Order Raxales. 131 

 Plants with succulent stems and leaves. 



Crassulaceae in Order Rosales. 157 

 Stamens on the margin of a hypanthium (the hj-panthium very 



small in some Saxifragaceae). Order Rosales. 157 



Carpels several and united. 

 f. Ovary superior, 

 g. Stamens inserted at the base of the ovary or receptacle, 

 h. Stamens numerous. 

 i. Sepals imbricated. 



Calyx deciduous. Order Papaverales. 144 



Calyx persistent. 

 Styles or stigmas distinct or united, but not discoid. 



Rutaceae in Order Geraniales. igz 



