18. Cruciferae 69 



19. Leaves palmatcly cleft and divided 16. Dentaria 



19. Leaves otherwise. 



20. Pubescence of simple hairs or none; leaves simple or 

 pinnately divided; valves of the pod nerveless, elas- 



tically dehiscent and recurving at maturity 



18. Cardamine 



20. Pubescence, at least in part, of branched hairs. 



21. Pods strongly flattened, 2-15 mm long; leaves chiefly 



basal (except D. brachycarpa) 15. Draba 



21. Pods slightly flattened, or nearly terete, more than 



1.5 cm long; stem leafy 19. Arabis 



18. Pods terete or tetragonal, not flattened. 



22. Valves of the pod conspicuously keeled, 3-nerved; leaves 

 deltoid-cordate, dentate, petiolate; plant with garlic odor 



10. Alliaria 



22. Valves of the pod rounded or flat. 



23. Leaves simple, pinnately lobed to entire. 



24. Petals 1.5-2 cm long, purple, or rarely white; leaves 



ovate-lanceolate, denticulate 12. Hesperis 



24. Petals less than 1.5 cm long. 



25. Petals purple; plant glabrous; lower leaves some- 

 times pinnatifid at the base, dentate, the upper 

 ones lanceolate, dentate, tapering to an auricu- 



late base; pods 2-3 cm long; stigma entire 



17. lodanthus 



25. Petals white; plant sparsely pubescent with forked 



hairs; pods 1-1.5 cm long; stigma 2-lobed 



20. Arabidopsis 



23. Leaves odd-pinnate with 1-11 roundish or oval leaflets; 

 petals white; mature pods 1-2 cm long, somewhat 



curved; aquatic glabrous perennial 21. Nasturtium 



14. Pods short, usually not more than three times as long as wide (a 

 silicle) . 

 26. Pubescence, if any, of simple hairs. 



27. Pods terete, ellipsoid, or subglobose, not flattened, plants 

 glabrous. 

 28. Basal leaves smaller, often finely divided (if in water) ; pods 



1-loculed, the style 2-3 mm long 22. Neobeckia 



28. Basal leaves 15-30 cm long, oval or ovate, crenate; root 



large, thick, pungent; pods 2-loculed, seldom maturing, 



the style 0.5 mm long 23. Armoracin 



27. Pods more or less compressed or flattened. 



29. Plants grayish-pubescent: upper leaves ovate, clasping, 



dentate, the lower oblanceolate; pods broadly ovate, in- 

 dehiscent, papillose, 4 mm broad, notched at the base, 



the style 1-2 mm long 29. Cardaria 



29. Plants green; pubescent or glabrous; pods suborbicular, 

 dehiscent, notched at the apex. 



30. Pods 2-seeded, less than 5 mm broad : branches 

 puberulent 30. Lepidium 



30. Pods several-seeded, 1-1.5 cm broad; plants glabrous 



31. Thlnspi 



26. Pubescence of forked or stellate hairs, at least on the stem. 



