KEY TO THE ORDERS. 



Plants with relatively firm stems and leaves, not succulent. 



Order 25. Ranales. 134 

 Plants with succulent stems and leaves. 



Crassulacea: in Order 27. Rosales. 169 

 Stamens on the margin of a hypanthium (the hypanthium very small 

 in some Saxif ragaceae) . Order 27. Rosales. 169 



. Carpels several and united. 

 a. Ovary superior. 



t Stamens inserted at the base of the ovary or receptacle. 

 § Stamens numerous. 

 Sepals imbricated. 



Calyx deciduous. Order 26. Papaverales. 148 



Calyx persistent. 



Styles or stigmas distinct or united, but not discoid ; land 



plants. Capparidacese in Order 26. Papaverales. 168 



Styles or stigmas united into a disk ; aquatic plants ; petals 

 and sepals numerous. 



Nymphasaceae in Order 25. Ranales. 147 

 Sepals valvate ; stamens with united filaments. 



Order 33. Malvales. 229 

 §§ Stamens few, not over twice as many as the petals. 

 Stamens as many as the petals and opposite them. 

 Anther-sacs opening by hinged valves. 



Berberidacese in Order 23- Ranales. 148 

 Anther-sacs opening by slits. 



Flowers monoecious. Order 30. Euphorbiales. 221 



Flowers perfect. 



Portulacacese in Order 24. Chenopodiales. -123 

 Stamens as many as the petals and alternate with them, or 

 more, sometimes twice as many. 

 Stamens 6 : petals 4 : sepals 2 or 4. 



Families in Order 26. Papaverales. 148 

 Stamens, petals and sepals of the same number, or stamens 

 more, usually twice as many as the sepals or petals. 

 Ovary i-celled. 



Ovules, or seeds, on basal or central placentae. 



Families in Order 24. Chenopodiales. 113 

 Ovules, or seeds, on parietal placentae. 



Stamens with united filaments and no staminodia. 



Order 33. Malvales. 229 

 Stamens with distinct filaments. 

 Staminodia present. 



Parnassiaceas in Order 27. Rosales. 17s 

 Staminodia wanting. 



Families in Order 34. Hypericales. 231 

 Ovary several-celled. 



Stamens adnate to the gynoecium. 



Asclepiadaceae in Order 43. Asclepiadales. 270 

 Stamens not adnate to the gynoecium. 



Stamens with wholly or partly united filaments. 

 Anthers opening lengthwise. 



Families in Order 28. Geraniales. 217 

 Anthers opening by pores. 



Order 29. Polygalales. 221 

 Stamens with distinct filaments. 

 Anthers opening by pores. 



Families in Order 39. Ericales. 258 

 Anthers opening by slits. 



Stigmas or styles distinct and cleft, or foliaceous, 



or united by pairs. Order 30. Euphorbiales. 221 

 Stigmas or styles all distinct or all united, neither 

 cleft nor foliaceous. 



