General Key to the Families 43 



XIV. ARNICA. L. 



1. A. cordifolia. Hook. Heart-leaved Arnica. 



2. A. latifolia. Bong. Broad-leaved Arnica. 



3. A. alpina. (L.) Olin. Alpine Arnica. 



4. A. Chamissonis. Less. Ckamisso's Arnica. 



5. A. Parryi. Gray. Parry's Arnica. 



6. A. louiseana. Farr. Schaeffer's Arnica. 



7. A. fulgens. Pursh. Notched Arnica. 



8. A. gracilis. Rydb. Slender Arnica. 

 XV. SENECIO. (Tourn.) L. 



1. S. Balsamitae. Muhl. Golden Ragwort. 



2. S. triangularis. Hook. Giant Ragwort. 



3. S. canus. Hook. Silvery Groundsel. 



4. S. lugens. Richards. Black-tipped Groundsel. 



5. S. pseudaureus. Rydb. Canada Ragwort. 



6. S. discoideus. (Hook.) Britton. Northern Squaw- 



weed. 



7. S. flavovirens. Rydb. Western Balsam Groundsel. 



TRIBE 



XVI. SAUSSUREA. 



i. S. densa. Hook. Purple Saussurea. 

 XVII. CARDUUS. (Tourn.) L. 



1. C. Kelseyi. White Thistle. 



2. C. foliosus. Hook. Leafy Thistle. 



3. C. undulatus. Nutt. Wavy-leaved Thistle. 



SERIES II. LIGULIFLORA 

 TRIBE CICHORIEyE 



XVIII. CICHORIUM. (Tourn.) L. 



i. C. Intybus. L. Chicory. 

 XIX. TARAXACUM. (Haller.) Ludwig. 



1. T. officinale. Weber. Common Dandelion. 



2. T. rupestre. Alpine Dandelion. 

 XX. SONCHUS. (Tourn.) L. 



i. S. arvensis. L. Sow Thistle. 



