240 
IOWA ACADEMY OF SCIENCE Vol. XXVIII, 1921 
28. Fitzpatrick, T. J. and M. F. E., Flora of Southern Iowa, II., Proc. 
Iowa Acad. Sci., Vol. VI, p. 180; 1899. 
29. Geiser, Samuel W., Bull, of Upper Iowa University, Biological 
Series, No. 2, p. 12; 1918. 
30. Gray, Asa, Field, Forest and Garden Botany, revised by E. H. Bailey, 
p. 106; 1895. 
31. Gray, Asa, Manual of the Botany of the Northern U. S., 6th ed., 
p. 112; 1890. 
32. Gray, Asa, New Manual of Botany, revised by B. E. Robinson and M. 
E. Fernald, 7th ed., p. 562; 1908. 
33. Greene, Wesley, Plants of Iowa, Bulletin of the Iowa State Horti- 
cultural Society, p. 191 ; 1907. 
34. Hayden, Ada, Notes on the Floristic Features of a Prairie Province 
in Central Iowa, Proc. Iowa Acad. Sci., Vol XXV, p. 376; 1919. 
35. Hitchcock, A. S., A Catalogue of the Anthophyta and Pteridophyta 
of Ames, Iowa, Contributions from the Shaw: School of Botany, 
No. 7, p. 489; 1891. 
36. Holzinger, J. M., Eist of Plants Collected by C. S. Sheldon and M. 
A. Carleton in Indian Territory in 1891, Contributions from the 
U. S. National Herbarium, Vol. 1, p. 190; 1896. 
37. Jackson, B. Daydon, Index Kewensis, Vol. I, p. 464; 1895. Supple- 
ments: 2nd, 1904 ; 3rd, 1908; 4th, 1913. 
38. Kearney, Thos. H., Report on a Botanical Survey of the Dismal 
Swamp Region, Contributions from the U. S. National Herbarium, 
Vol. V, p. 533; 1901. 
39. Kellerman, W. A., The Fourth State Catalogue of Ohio Plants, p. 
32; 1899. 
40. Kellerman, W. A., Gleason, H. A., and Schaffner, J. H., Spring 
Flora, p. 93; 1906. 
41. Einne, C., Species Plantarum, p. 195; 1753. 
42. Macbride, Thos. H., Forestry Notes for Dubuque County, Iowa Geol. 
Survey, Vol. X, p. 632; 1900. 
43. MacMillan, Conway, The Metaspermae of the Minnesota Valley, 
Geol. and Natural Hist. Survey of Minnesota, Botanical Series I, 
pp. 355-356; 1892. 
44. MacMillan, Conway, Minnesota Plant Eife, Geol. and Natural Hist. 
Survey of Minnesota, Botanical Series III, p. 319; 1899. 
45. Macoun, John, Catalogue of Canadian Plants, Part I, Geological 
Survey of Canada, pp. 95-96; 1883. 
46. Mohr, Chas., Plant Eife of Alabama, Contributions from the U. S. 
National Herbarium, Vol. VI, pp. 88, 610; 1901. 
47. Mueller, H. A., Shrubs and Trees of Madison County, Proc. Iowa 
Acad. Sci., Vol. VIII, p. 199 1901. 
48. Mueller, H. A., A Preliminary Eist of the Flowering Plants of 
Madison County, Proc. Iowa Acad- Sci., Vol. XI, p. 264; 1904. 
49. Oleson, O. M., and Somes, M. P., A Flora of Webster County, Iowa, 
Proc. Iowa Acad. Sci., Vol. XIII, p. 46; 1906. 
50. Pammel, E. H., Notes on the Flora of Western Iowa, Proc. Iowa 
Acad. Sci. Vol. Ill, p. 115; 1896. 
51. Pammel, E. H., Flora of Story County, Iowa Geol. Survey, Vol. IX, 
p. 242; 1899. 
52. Perry, C. C., In D. D. Owen’s Report on the Geol. Survey of Wis., 
Iowa and Minn., p. 610; 1852. 
53. Parry, C. C., The North American Genus Ceanothus E., Proc. Dav- 
enport Acad. Sciences, Vol. V, pp. 162-174; 1889. 
54. Peck, Morton E., The Flowering Plants of Hardin County, Proc. 
Iowa Acad. Sci., Vol. XII, p. 222; 1905. 
55. Perkins, Geo. H., A General Catalogue of the Flora of Vermont, p. 
11; 1882. 
56. Peterson, N. F., Flora of Nebraska, p. 152; 1912. 
