VALERIANACEAE. 327 



2. Valeriana trachycarpa Rydb. In the mountains of Colo, and N. M. 

 Alt. 8000-10,000 ft. Red Mountain; Alpine Tunnel; Marshall Pass; Rabbit- 

 Ears Pass. 



3. Valeriana furfurascens A. Nelson. On hillsides and mountains of Wyo. 

 and Colo. Alt. 7000-10,000 ft. Bosworth's ranch; Narrows; Pike's Peak; 

 Ruxton Dell; Indian Pass Creek. 



4. Valeriana micrantha A. Nelson. In the mountains from Mont, and Ida. 

 to Colo, and Utah. Alt. about 9000 ft. West Mancos Canon; Rabbit-Ears, 

 Larimer Co. 



5. Valeriana ovata Rydb. In the mountains of Colo, and N. Mex. Alt. 

 up to 9500 ft. Cameron's Cone. 



6. Valeriana acutiloba Rydb. (V. oreophila Greene) In the mountains 

 from Wyo. and Utah to N. M. and Ariz. Alt. 8000-13,500 ft. Silverton ; 

 Beaver Creek; mountains about Ouray; mountains above Graymont; Ragged 

 Mountains; Cameron Pass; Pike's Peak; Clear Creek; mountain near Veta 

 Pass; near Pagosa Peak; Bear Creek Canon; Mt. Hesperus; Mt. Abram, 

 Ouray; Ruxton Dell; Gray's Peak; Carson; Grayback mining camps and 

 Placer Gulch ; Salida ; Boreas ; Mt. Richtofen. 



7. Valeriana occidentalis Heller. In wet places in the mountains from Ida. 

 and Mont, to Colo, and Utah. Canon of Cache la Poudre; Poverty Ridge, 

 above Cimarron ; Anita Peak ; Beaver Creek. 



Order 49. CARDUALES. 



Flowers all with tubular corollas or none, or only the ray-flowers with ligulate 



corollas. 



Stamens distinct; flowers unisexual. 132. AMBROSIACEAE. 



Stamens united by the anthers, or if distinct (in Kuhnia) the flowers her- 

 maphrodite. 133. CARDUACEAE. 

 Flowers all with ligulate corollas. 134. CICHORIACEAE. 



Family 132. AMBROSIACEAE Reich. RAGWEED FAMILY. 



Staminate and pistillate flowers in the same heads ; the latter few (rarely 



solitary or none), at the margins. 

 Achenes turgid, ovoid or pear-shaped, marginless. 



Involucres of 5 dilated ovate, rigidly acuminate bracts ; achenes with a 



large terminal areola, surrounded by a disk. i. OXYTENIA. 



Involucres not with dilated rigidly acuminate bracts ; terminal areola minute. 



2. IVA. 



Achenes flattened, wing-margined ; involucres of 5 ovate or oblong herbaceous 

 bracts and within them 1-2 large scarious bracts subtending the pistillate 

 flowers. 3. DICORIA. 



Staminate and pistillate flowers in different heads ; the latter 14, without corolla, 



and enclosed in a nut-like or burr-like involucre. 



Involucres of the Staminate heads with united bracts ; receptacles low ; rudi- 

 mentary styles penicillate or fimbriate at the apex. 

 Spines or tubercles of the i -flowered pistillate heads in a single row. 



4. AMBROSIA. 

 Spines of the i-4-flowered pistillate heads in more than one row. 



5. GAERTNERIA. 

 Involucres of the Staminate heads with distinct bracts ; receptacle cylin- 



draceous ; spines of the 2-flowered pistillate heads in several rows, uncinate. 



6. XANTHIUM. 



