KEY TO THE OKDEKS. Xlll 



Stamens perigynous or epigynous, inserted on the margin of a 



hypanthium or a disk. 



Fruit a samara. Families in Order SAPINDALES. 



Fruit not a samara. 



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



Order RHAMNALES. 



Fruit a capsule : herbs. Order ARISTOLOCHIALES. 



b. 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. 



Herbs, with succulent stems and leaves, or woody below : 

 flowers perfect. Tetragoniaceae in Order CHENOPODIALES. 

 Trees or shrubs : flowers dioecious. 



Nyssaceae in Order AMMIALES. 

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



or twice as many. 

 Styles present. 



Ovules mostly on basal placentae, sometimes pendulous : 

 cotyledons not convolute : tree- or root-parasites. 



Order SANTALALES. 



Ovules not on basal placentae : cotyledons convolute : not 

 parasitic plants. Families in Order MYKTALES. 



Styles wanting : stigmas sessile. 



Gunneraceae in Order MYRTALES. 

 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 cavities in 



the ovary, or irregular. Order ARISTOLOCHIALES. 



Calyx regular and the sepals as many as the cavities in the 



ovary. Order MYRTALES. 



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



Saxifragaceae in Order ROSALES. 

 Flowers, at least the staminate, in involucrate heads. 



Ambrosiaceae in Order CARDUALES. 

 B. Corolla present. 



* 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. 



Flowers not in monoecious heads. 



Plants with relatively firm stems and leaves, not succulent. 



Order RANALES. 

 Plants with succulent stems and leaves. 



Sedaceae in Order ROSALES. 



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

 some Saxifragaceae). Order ROSALES. 



Carpels several and united. 

 t Ovary superior. 



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

 Stamens numerous. 

 Sepals imbricated. 



Calyx deciduous. Order PAPAVERALBS. 



Calyx persistent. 



Styles or stigmas distinct or united, but not discoid. 

 Leaves glandular or pellucid-punctate. 



Rutaceae in Order GERANIALES. 

 Leaves not glandular. 



Capparidaceae in Order PAPAVERALES. 

 Styles or stigmas united into a disk. 



Petals and sepals numerous : leaves with flat blades : 

 aquatic plants. Nymphaeaceae in Order RANALES. 

 Petals and sepals few : leaves with pitcher-like organs : 

 bog plants. 



Sarraceniaceae in Order SARRACENIALES. 

 Sepals valvate. 



Stamens with distinct filaments. 



Ovary 1-celled : placentae parietal. 



Capparidaceae in Order PAPAVERALES. 

 Ovary 2-several-celled : placentae axile or central. 



Families in Order MALVALES. 



Stamens with united filaments. Order MALVALES. 



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. 



Podophyllaceae in Order RANALES. 

 Anther-sacs opening by slits. 



