Vlll 



EY TO THE FAMILIES. 



Stamens perigynous. 

 Stamens hypogynous. 

 Pistil one. 



Anthers opening by uplifted 



valves. 



Anthers not opening by up- 

 lifted valves. 



Ovary more than 1-celled. 

 Ovary 2-celled. 

 Ovary more than 2- 



celled. 



Ovary 6-celled. 

 Ovary 3-5-celled. 

 Ovary 1-celled. 



Ovary partly inferior. 

 Flowers on a scape. 

 Flowers on a leafy 



stem. 



Ovary superior. 

 Fruit an akene. 

 Akene enclosed 

 in the re- 

 ceptacle. 

 Akene not en- 

 closed in the 

 receptacle. 

 Fruit not an akene. 

 Fruit a utricle. 

 Fruit a capsule. 

 Stamens 8. 

 Stamens 5. 



ROSACEAE, 197. 

 RANUNCULACEAE, 151. 



AcMys, 164. 



CRUCIFERAE, 166. 



ARISTOLOCHIACEAE, 124. 

 AIZOACEAE, 136. 



Heuchera, 196. 

 SANTALACEAE, 124. 



ROSACEAE, 197. 



POLYGONACEAE, 125. 

 CHENOPODIACEAE, 132. 



Chrysosplenium, 193. 

 Claytonia, 139. 



B. Petals Present. 



1. Stamens numerous, at least more than ten 

 sepals or calyx-lobes. 



Calyx free and separate from the ovary. 

 Pistils more than one. 



Ovaries cohering in a ring around a central 



axis. 

 Ovaries separate, or, if united, not cohering 



in a ring around a central axis. 

 Stamens perigynous. 

 Stamens hypogynous. 



Aquatic plants; leaves not dissected. 

 Terrestrial plants, or, if aquatic, the 



submersed leaves dissected. 

 Pistil one, with one to several styles and stig- 

 mas. 

 Leaves minutely punctate with pellucid 



dots. 



Leaves not punctate with pellucid clots. 

 Ovary simple. 



Stamens hypogynous. 

 Stamens perigynous. 

 Ovary compound. 



and more than twice the 



MALVACEAE, 238. 



ROSACEAE, 197. 

 NYMPHAEACEAE, 150. 

 RANUNCULACEAE, 151. 



HYPERICACEAE, 239. 



RANUNCULACEAE, 151. 

 ROSACEAE, 197. 



