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 Caiion ; 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. — Caiion 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 Knhnia) 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 1-4, 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 1-4-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. 



