244 EPILOBIACEAE. 



3. Gayophytum Nuttallii T. & G. On hillsides from S. D. and Wash, to 

 Colo., Ariz, and Calif. Alt. 6000-8000 ft. Parlin, Gunnison Co. ; foot-hills, 

 Larimer Co. 



4. Gayophytum racemosum T. & G. In sandy soil from Wyo. and Wash, to 

 Colo, and Calif. Alt. 5000-12,000 ft. Headwaters of Clear Creek; Veta 

 Pass ; above Mancos ; along the Poudre. 



4. ONAGRA Adans. EVENING PRIMROSE. 



Hypanthium slender, 2.5-5 cm. long. 



Petals 12 cm. long, yellow ; pubescence rarely hirsute. 



Plant green; capsule 3-4 cm. long. i. O. Oakesiana. 



Plant grayish strigose ; capsule 23 cm. long. 2. O. strigosa. 



Petals 2-3.5 cm. long, often pinkish; plant more or less hirsute. 



3. O. Hookeri. 



Hypanthium stout, 613 cm. long. 4. O. Jamesii. 



1. Onagra Oakesiana (A. Gray) Britton. (Oenothera Oakesiana A. Gray) 

 In rich valleys from Que. and S. D. to N. Y. and Colo. Alt. up to 10,000 ft. 

 Salida ; North Cheyenne Canon ; Valley Spur. 



2. Onagra strigosa Rydb. In valleys and on plains from Minn, and Wash, 

 to Kans., N. M. and Utah. Alt. 4000-7000 ft. Ft. Collins ; Colorado Springs ; 

 Gunnison ; Elk River, Routt Co. ; Engelmann Canon ; Poudre Canon ; Gyp- 

 sum; soldier Canon. 



3. Onagra Hookeri (T. & G.) Small. (Oenothera Hookeri T. & G. ; O. 

 biennis hirsutissima A. Gray) In valleys from Ida. to N. M. and Calif. ; 

 also Mex. Alt. 6000-10,000 ft. Black Canon of Gunnison; Canon City, 

 Fremont Co.; Pagosa Springs; Parrott Post Office; west of Ouray; Waha- 

 toya Creek; Pike's Peak; Durango; along Conejos River north of Antonito. 



4. Onagra Jamesii (T. & G.) Small. (Oenothera Jamesii T. & G.) In 

 dry soil from Okl. and Utah to Tex. and Ariz. On Platte River (?). 



5. ANOGRA Spach. WHITE EVENING PRIMROSE. 



Calyx in bud merely acutish ; tips not free. 



Capsule divergent or reflexed. i. A. violacea. 



Capsule erect or ascending. 2. A. albicaulis. 



Calyx in bud acuminate or acute ; tips free. 



Capsule linear-cylindric ; throat of the calyx glabrous. 



Calyx sparingly long-hairy, glandular-puberulent or glabrous, not strigose. 

 Leaves deeply pinnatifid. 3. A. rhizomata. 



Leaves subentire, dentate or short-lobed. 



Capsules strongly ascending, straight ; leaves linear, entire or nearly so, 



strigose beneath. 4. A. Nuttallii. 



Capsules divergent, usually curved upwards ; leaves usually denticulate 



or sometimes lobed. 



Leaves glabrous, except the margins. 5. A. Vreelandii. 



Leaves pubescent on both sides. 6. A. cinerea. 



Calyx and hypanthium densely grayish strigose ; leaves cinerous. 



7. A. lati folia. 

 Capsules oblong ; throat of the calyx hairy ; leaves deeply pinnatifid. 



8. A. coronopifolia. 



i. Anogra violacea A. Nels. In sandy soil of Wyo. and Colo. Alt. 4000- 

 5500 ft. Deer River; Palisades; Hotchkiss. 



