162 BRASSIACEAE. 



Pubescence dense and grayish ; stem-leaves entire-margined or mi- 

 nutely denticulate. 16. D. Helleriana. 

 Style i mm. long; pod decidedly pubescent. 

 Stem erect or nearly so. 



Leaves thin ; basal ones usually over 2 cm. long ; cauline ovate to 



lanceolate. 

 Petals 5 mm. or more long ; stem-leaves often dentate. 



17. D. luteola. 

 Petals 3-4 mm. long; stem-leaves entire-margined. 



1 8. D. aureformis. 

 Leaves thick ; basal ones 1-2 cm. long ; cauline lanceolate or oblong. 



19. D. aurea. 

 Flowering stem decumbent ; leaves finely stellate ; pods twisted. 



20. D. decumbens. 



1. Draba micrantha Nutt. (D. caroliniana micrantha A. Gray) In arid 

 soil from 111. to Wash., Tex. and N. M Alt. 4000-6000 ft. Mancos ; Denver ; 

 foot-hills west of Ft. Collins. 



2. Draba coloradensis Rydb. (D. cuneifolia Coult, in part; not Nutt.) On 

 plains and hillsides of Colo. Alt. 4000-5500 ft. Hills west of Soldier Canon ; 

 Ft. Collins ; Mancos ; foot-hills west of Ft. Collins ; plains near Denver ; near 

 Boulder; New Windsor. 



3. Draba nemorosa L. In dry places, often among grass, from Mich, to 

 Mont., B. C, Colo, and Ore. Alt. 4000-10,000 ft. Georgetown; mountain 

 near Veta Pass; foot-hills west of Ft. Collins; headwaters of Sangre de 

 Cristo Creek ; Rist Canon ; Horsetooth Gulch ; Poudre River ; west of Soldier 

 Canon; Howe's Gulch; near Chambers' Lake; Parlin, Gunnison Co.; Middle 

 Park; Georgetown. 



4. Draba montana S. Wats. In the mountains of Colo. Alt. up to 2700 m. 

 Ironton Park, 9 miles south of Ouray. 



5. Draba lutea Gilib. (D. nemorosa leiocarpa, in part) On hillsides from 

 Hudson Bay to Alaska, Mich., Colo, and Ore. Idaho Springs; Georgetown; 

 Rabbit-Ear Range, Routt Co. 



6. Draba nitida Greene. (D. stenoloba Wats. & Brew.; not Ledeb.) On 

 hillsides from Wyo. to Ore., Colo, and southern Calif. Alt. 8000-11,000 ft 

 Near Teller, North Park; Tennessee Pass; Cameron Pass; mountains east 

 of Cameron Pass; Grayback mining camps; Flat Top Mountains; Marshall 

 Pass; Sargent's; South Park; near Chambers' Lake. 



7. Draba crassifolia Graham. On exposed mountain-tops from Greenl. to 

 B. C., Colo, and Utah. Alt. 10,000-14,000 ft. Mountains northeast of 

 Boreas; near Ironton, San Juan Co.; vicinity of Como; Leroux Creek, Delta 

 Co.; Sierra Blanca; Massif de 1'Arapahoe; summit of North Park Range, 

 Larimer Co. 



8. Draba Parryi Rydb. On alpine peaks of Colo, and Wyo. Alt. 10,000- 

 13,000 ft. Foot of Gray's Peak ; Cameron Pass ; Cumberland Basin, La Plata 

 Mountains ; Red Mountain ; Alpine Tunnel. 



9. Draba fladnizensis Wulf. In arctic regions and on alpine peaks, on 

 wet rocks, from Lab. and B. C. to Colo, and Utah. Alt. about 13,000 ft 

 Gray's Peak trail; Gray's Peak; West Spanish Peaks; Parlin. 



10. Draba cana Rydb. (D. incana confusa of Coult. Man.; not Poir.) In 

 the mountains, among rocks, from Lab. and Yukon to Colo. Alt 11,000-12,000 

 ft. Massif de 1'Arapahoe; northeast of Boreas; Red Mountain; Pike's Peak. 



