Key to the System of 



15. Sepals or lobes of the calyx overlapping before expansion 16 



Sepals or lobes of the calyx contiguous at the margin 

 before expansion ... ... ... ... 31 



16. Seeds fixed to the walls of the fruit-cavity 17 



Seeds, when more than one, fixed away from the walls of 

 the fruit-cavity ... 21 



17. Sepals often two. 



Sepals fugacious ; petals generally four, usually almost 

 equal ; embryo minute, at the base of the albument. 



Fapaveraceae. 118 



Sepals often four or five ... ... ... ... 18 



18. Sepals generally four ... ... ... ... 19 



Sepals generally five ... ... 20 



19. Stamens usually six, two of them shorter. 



Sepals always four ; petals generally four, usually almost 

 equal ; fruit often deciduously bivalved and longitudinally 

 two-celled ; albument none. Figure 8. Cruciferae. 119 



Stamens usually indefinite in number. 



Sepals often four ; petals generally four, usually almost 

 equal ; fruit one-celled ; albument none. Figure 7. 



Capparideae. 131 



20. Petals equal. 



Herbs beset with glandular-hairlets ; leaves and flower- 

 stalks coiled before expansion ; sepals, petals and stamens 

 often five ; petals persistent, extremely tender : fruit de- 

 hiscent, often one-celled. Figure 11. Droseraceae. 132 



Petals usually very unequal. 



Sepals, petals and stamens five ; filaments flat, extending 

 beyond the anthers ; fruit one-celled. Figure 9. 



Violaceae. 133 



21. Fruit lobeless 22 



Fruit often lobed or finally separable into fruitlets ... 25 



