162 BRASSIACEAE. 



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

 nutely denticulate. i6. 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. 



18. D. aureformis. 

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



19. D. aurea. 

 Flowering stem decumbent ; leaves finely stellate ; pods twist,ed. 



20. D. decumbens. 



1. Draba micrantha Nutt. (D. caroUniana 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 virest of Soldier Caiion; 

 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 

 Cation; 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. (£). 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 Come ; 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. (Z?. 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 I'Arapahoe; northeast of Boreas; Red Mountain; Pike's Peak. 



