PLATE IX. 



X. inflexum Mack, and Bush. 



F. i. Bush, 1916 (Hb. Gray, type material). 



F. 2. Engelmann (Hb. Mo. 85551). 



F. 3. Bush 1806 (Hb. Mo. 85522). 



F. 4. Bush 1806 (Hb. Gray). 

 X. pennsylvanicum Wallr. 



F. 5. Greene (Hb. Greene 19822; type of X. calif ornicum Greene). 



F. 6. Sanford (Hb. Greene 19819, type of X. acutum Greene). 



F. 7. Reverchon 2589 (Hb. Mo. 85546). 



F. 8. Suksdorf 1584 (Hb. Mo. 85374; cotype of X. affine Greene). 



F. 9. Lansing 3532 (Hb. Field 346590). 



F. 10. Heller 7550 (Hb. N. Y.). 

 X. calvum Millsp. and Sherff. 



Ff. ii and 12. Baker 1760 (Hb. Calif. 131236, type). 

 X. palustre Greene. 



F. 13. Greene (Hb. Greene 19834, type material). 



F. 14. Greene (Hb. Greene 10833, type material). 



F. 15. Walker 973 (Hb. Calif. 128022). 

 X. australe Millsp. and Sherff. 



F. 1 6. Palmer 275 (Hb. U. S. 463216, type). 



F. 17. Dr. Mertens, Valparaiso, Chile (ex Hb. Acad. Petrop., in Hb. Gray). 



F. 18. Morong 807 (Hb. N. Y.): 

 X. echinatum Murr. 



F. 19. Sturteyant (Hb. Mo. 85500). 



F. 20. Victorin 1056 (Hb. Gray). 



F. 21. Miss M. E. Blatchford, Prouts Neck, Me., Sept., 1898 (Hb. Gray). 

 X. acerosum Greene. 



F. 22. J. H. Schuette, Baird's Creek, Preble, Brown County, Wis., Sept. 26, 1899 

 (Hb. Gray). 



F. 23. Burnham 28 (Hb. Gray). 



F. 24. Lunell 80 (Hb. Gray). 

 X. italicum Mor. 



F. 25. Suksdorf 1583 (Hb. Field 89751, cotype of X. varians Greene). 



F. 26. Macoun 11415 (Hb. Can. 11415, type of X. Macounii Britton). 



F. 27. Macoun 10910 (Hb. Can. 10910, type material of X. glanduliferum 

 Greene). 



F. 28. Sherff 3081 (Hb. Field 480739, matching fruits on Moretti's specimen in 

 Hb. De Candolle). 



F. 29. Bruyas, gravelly fields along banks of the Arc River, Aix Bouches-du- 

 Rhone, France, Sept. 27, 1884 (Hb. Field 331608). 



F. 30. Rose and Fitch 17507 (Hb. U. S. 760583). 



