EDWIN BLAKE PAYSON 
Leaves with simple or branching hairs i. D. alpina. 
Style evident (over ,5 mm. long). 
Pods globose 22. D. sphaeroides. 
Pods flattened. 
Pods 3-4 mm. long. 
Leaves obovate 21. D. uncinalis. 
Leaves linear 9. P. oligosperma. 
Pods over 5 mm. long. 
Leaves broadly linear 14. D. laevicapsula. 
Leaves broadly spatulate or oblanceolate. 
Leaves densely stellate and silvery 24. D. argyrea. 
Leaves more sparsely pubescent, green. 
Pods narrowly lanceolate, not over 2 
mm, wide 20. D. cruciata. 
Pods broader (3 mm. or more). 
Hairs mostly cruciform 17. D. aster ophora. 
Hairs simple or branching i., D. alpina. 
ds pubescent. 
Seeds winged, leaves silvery 23. D. pterosperma. 
Seeds not winged. 
Pods globose, stellate pubescent 25. D. sphaerocarpa^ 
Pods more or less flattened. 
Leaves densely imbricated, not over 5 mm. long, 
silvery stellate, cilia absent 26. D. suhsessilis. 
Leaves not so densely imbricated, mostly over 
5 mm. long. 
Leaves linear or slightly spatulate. 
Fruiting raceme corymbose 11. D. vestita. 
Fruiting raceme elongated. 
Stellate hairs sessile, near apex of leaf. . .8. D. oligosperma. 
Stellate hairs not sessile nor usually 
restricted to apex of leaf. 
Ciliations not conspicuous, plants 
not soboliferous 9. D.incerta. 
Ciliations conspicuous, plants so- 
boliferous 18. D. Mulfordae. 
Leaves not linear. 
Leaves silvery- white, entirely stellate 24. D. argyrea. 
Leaves greenish, or if silvery, cilia evi- 
dent. 
Pods narrowly lanceolate 20. D. cruciata. 
Pods broader (3 mm. or more). 
Style .5 mm. long, plants of 
Hudson Bay 10. D. Bellii. 
Style I mm. long or more (usually). 
Ciliations numerous and con- 
spicuous 18, D. Mulfordae. 
