402 CARDUACEAE. 



and hills from Mich., Ass. and Mont, to Tex. and Utah. Alt. 4000-7000 ft. 

 Georgetown; near Grand Junction; Durango; Wolcott; Golden. 



28. Carduus megacephalus Nutt. (Cnicus undulatus megacephalus A. Gray) 

 On prairies, plains and hills from, S. D. and Ida. to Mo., Tex. and Colo. 

 Alt. 4000-7500 ft. Idaho Springs; Boulder; Cucharas Valley, near La Veta; 

 Ft. Collins; Spring Canon; Turkey Creek. 



29. Carduus ochrocentrus (A. Gray) Greene. (Cnicus ochrocentrus A. 

 Gray) On plains from Neb. and Colo, to Tex. and Ariz. Alt. 4000-5000 ft. 

 Ft. Collins; New Windsor. 



30. Carduus filipendulus (A. Gray) Rydb. (Cirsium filipendulum Engelm. ; 

 Cnicus altissimus filipendulus A. Gray) On prairies, valleys and waste 

 places from Colo, to Tex. Clear Creek Valley; Ft. Collins. 



31. Carduus arvensis (L.) Robs. (Cnicus arvensis Hoffm.) In fields and 

 waste places; an introduced weed from Europe and naturalized from Newf. 

 and Ida. to N. J. and Colo. Alt. 4000-5000 ft. Livingstone; Ft. Collins. 



32. Carduus neo-mexicanus (A. Gray) Greene. (Cnicus Neo-Mexicanus 

 A. Gray; C. leucopsis Greene) On plains from Colo, to N. M. and Ariz. 

 Alt. 4000-6000 ft. Grand Junction; Arboles; Rifle, Garfield Co. 



Family 134. CICHORIACEAE Reich. CHICORY FAMILY. 



I. Pappus of plumose bristles, often more or less paleaceous at the base. 

 Achenes truncate at the apex, not beaked. 



Flowers yellow; simple plants with fusiform roots. i. PTILOCALAIS. 



Flowers pink, rose or white ; branched plants with rush-like stems. 



2. PTILORIA. 

 Achenes with long beaks ; simple plants with fistulose leaves. 



3. TRAGOPOGON. 



II. Pappus not plumose. 



A. Pappus consisting, at least partly, of chaffs or these reduced and united into 



a crown. 

 Involucres simple and naked, *. e., without smaller calyculate bracts below; 



pappus of both chaffs and bristles ; flowers yellow. 4. ADOPOGON. 



Involucres double, either imbricated or with smaller calyculate bracts below ; 



flowers blue. 5. CICHORIUM. 



B. Pappus of capillary bristles, not plumose, slightly if at all broadened below, 

 i. Achenes not flattened. 



a. Pappus-bristles promptly deciduous, mainly together; only a few of the 

 stouter ones in some species remaining. 6. MALACOTHRIX. 



b. Pappus persistent, tardily falling off separately, or together only by 



the breaking off of the beak. 

 Beaks of the achenes none or a mere attenuation. 

 Flowers rose or purplish. 



Stems rush-like and striate ; leaves narrowly linear or reduced ; 



achenes tapering at the summit. 7. LYGODESMIA. 



Stems not rush-like ; leaves ample ; achenes tapering to the base. 

 Annuals ; heads 4-5-flowered ; achenes with 4-5 strong ribs. 



8. PRENANTHELLA. 

 Perennials ; heads 8-30-flowered (rarely less) ; achenes terete or 



4-5-angled. 9. NABALUS. 



Flowers yellow or white. 



Heads several, rarely solitary ; stem leafy. 



Achenes tapering upwards ; pappus white ; bracts in fruit more 

 or less thickened at the base or on the mid-rib. 



10. CREPIS. 



Achenes not tapering upwards ; pappus in ours sorded or reddish ; 

 bracts not thickened. n. HIERACIUM. 



