FABACEAE. 207 



4. Xylophacos vespertinus (Sheld.) Rydb. (A. vespertinus Sheld.) In 

 arid places of W. Colo, and N. Mex. — Grand Junction. 



5. Xylophacos Shortianus (Nutt.) Rydb. (^A. Shortianus Nutt.) On 

 plains and dry hills from western Neb. and Wyo. to Colo, and Ariz. — Alt. 

 4000-9000 ft. — Ute Pass; plains near Denver; Clear Creek Canon; Ft. Col- 

 lins; Rist Caiion; Spring Cafion; west of Dixon Canon; Hotchkiss; Table 

 Rock; Soldier Canon; vicinity of Horsetooth; Grand Junction; north of La 

 Porte; near Boulder; Sapinero; Arboles. 



6. Xylophacos amphiozus (A. Gray) Rydb. {A. amphioxus A. Gray) 

 On dry plains and hills from southwestern Colo, to Utah and Ariz. — Exact 

 locality not given. 



7. Xylophacos uintensis (Jones) Rydb. {Astragalus Uintensis Jones) 

 On dry mesas from Colo, to Utah and Ariz. — Alt. 4000-7000 ft. — Mancos; 

 mesas near Pueblo; Cimarron; Grand Junction. 



8. Xylophacos Newbenyi A. Gray. Dry hills from southwestern Colo, 

 and Utah to N. M. and Ariz. — Exact locality not given. 



9. Xylophacos Purshii Dougl. On plains and hills from Mont, and B. C. 

 to northern Colo, and Calif. — Along North Platte. 



19. CTENOPHYLLUM Rydb. 



I. Ctenophyllum pectinatum (Hook.) Rydb. (Phaca pectinata Hook.; 

 Astragalus pectinatus Dougl.) On dry plains from Alb. and Sask. to Kans. 

 and Colo. — Ft. Collins. 



20. CNEMIDOPHACOS Rydb. 



I. Cnemidophacos flavus (Nutt.) Rydb. {Astragalus Aavus Nutt.) On 

 dry mesas from Wyo. to N. M. — Alt. about 6000 ft. — Grand Junction; Man- 

 cos; Arboles. 



21. MICROPHACOS Rydb. 



I. Microphacos microlobus (A. Gray) Rydb. {Astragalus microlobus A. 

 Gray) On plains and hills from S. D. and Mont, to Kans. and Colo. — Alt. 

 4000-7000 ft. — Ft. Collins; Walsenburg; New Windsor; mesas near Pueblo; 

 Cucharas Valley, near La Veta; Denver; Colorado City. 



22. DIHOLCOS Rydb. 



Corolla over i cm. long ; calyx-teeth nearly as long as the tube. 



Corolla purplish or pinkish; pod strigose. 1. D. bisulcatus. 



Corolla whitish ; pod glabrous. i. D. decalvans. 



Corolla whitish or straw color, less than i cm. long ; calyx-teeth much shorter than 



the tube. 3. D. Haydenianus. 



1. Diholcos bisulcatus (Hook.) Rydb. {Phaca bisulcata Hook.; Astragalus 

 bisulcatus A. Gray) On plains and in river valleys from Sask. and Mont, to 

 Neb. and Colo. — Alt. 4000-8000 ft. — Pueblo; between La Veta and Gardner; 

 Ft. Collins; mesas near Pueblo; Lamar; Spring Caiion; Platte River; 

 Colorado Springs. 



