The American Midland Naturalist 



PUBLISHED BI-MONTHLY BY THE UNIVERSITY 

 OF NOTRE DAME, NOTRE DAME, INDIANA. 



VOL. III. JANUARY, 1913. NO. 1. 



Erigeron in North Dakota.— II. 



BY J. LUNELL. 



When publishing E. multicolor in the issue of this journal 

 for July 19 1 2, the manuscript having been written some weeks 

 beforehand, I intimated that I expected to collect during the 

 incumbent season additional material of specimens standing near 

 to this species in general appearance, but with some characters 

 more or less different. The result was richer indeed than antici- 

 pated, and before introducing these plants, I only wish to em- 

 phasize that whatever the merit is of this paper, it has been en- 

 hanced by many valuable suggestions from Dr. E. L. Greene which 

 herewith are appreciatively acknowledged. It is worth adding 

 that in the species where there is a dentation of the leaves, the 

 teeth are as a rule quite small, often needing the aid of a lens 

 to be recognized, and in poorly developed individual plants this 

 dentation is rudimentary and often altogether absent. 



In order to draw the difference between the species belonging 

 to this group of daisies, I believe the following key will be helpful: 



Clavis Analytica. 

 A. Flores radiati 6-8 mm. longi, angusti. 

 a. Folia Integra. 



b. Caules hirsuto-scabri i. E. asper Nutt. 



b. Caules pilis mollibus longitudinis inequalis 

 repandis et appressis tenuiter ves- 



titi 8. E. asper var. appressus. 



a. Aliquot saltem folia dentata. 



c. Folia inferiora plerumque brevia et lata.. 9. E. ahruptorum. 



c. Folia inferiora spatulato-lanceolata 2. E. multicolor. 



c. Folia inferiora longa, angusta, tenuiter 

 aculeata. 



