KEY TO THE FAMILIES 23 



B. Stamens on the corolla. 



1. Stamens more than 5 (and ovary superior). 



Petals 4, in pairs ; sepals 2; stamens 6 Dicentra, 102 



Petals 5. 



Pistils 4 or 5, distinct; stamens 10 Crassulaceae, 113 



Pistil 1. 

 Flowers very irregular; stamens 10; ovary 1- 



celled Leguminosae, 135 



Flowers regular; stamens many, united into a 



tube. . N Malvaceae, 157 



2. Stamens 5 or less. 

 Calyx free from the ovary. (Ovary superior.) 

 (For "Calyx adherent," see p. 24.) 

 Corolla regular (i. e., the lobes all alike). 



Ovaries 2, becoming a pair of pods when both 

 mature. 

 Stamens lightly united or distinct, not attached 



to the stigmas Apocynaceae, 187 



Stamens united, and adherent to the stigmas, the 



column bearing hood-like appendages 



Asclepiadaceae, 188 

 Ovary 1, 4-lobed, forming 4 nutlets. 



Leaves alternate, not aromatic Boraginaceae, 203 



Leaves opposite, aromatic Labiatae, 207 



Ovary 1, entire. 



Style 3-cleft at apex; capsule 3-celled. . Polemoniaceae, 190 

 Styles or stigmas 2 or 1. 

 Stamens opposite the divisions of the corolla. 



Primulaceae, 182 

 Stamens alternate with the divisions of the 

 corolla. 

 Leaves heart-shaped at base, as broad as 



long, or wanting Convolvulaceae, 190 



Leaves not heart-shaped at base. 



Stemless plants ; leaves (simple) all at base 



of a naked flower-stalk Plantaginaceae, 230 



Stems present and bearing leaves. 

 Herbage perfectly glabrous; leaves all 

 opposite (or whorled) and entire; 



capsule 1-celled Gentianaceae, 185 



Herbage more or less pubescent; leaves 

 various. 

 Styles 2, or 1 and 2-cleft; capsule 1 



or 2-celled Hydrophvllaceae, 197 



