502 FABACEAE 



3. C. adanum (A. Nels.) Rydb. Steins many, glabrate, striate, 2-4 dm. 

 high; leaflets 13-25, rather thin, from oblong to broadly obovate, 7-14 mm. 

 long, glabrous above, sparingly strigose beneath; racemes 5-15-flowered, short- 

 peduncled; calyx partly black-hairy; pod narrowly ovoid, with short incurved, 

 compressed apex, about 1 cm. long. A. adanus A. Nels. Hills: Ida. Je. 



29. CNEMIDOPHACOS Rydb. 



Cespitose perennials with a woody caudex; stems short, 1-2 dm. high. Leaves 

 pinnate, with many narrow leaflets, cinereous; stipules slightly united with the 

 petioles, but almost wholly united behind the stem, forming a sheath. Racemes 

 strict and many-flowered. Calyx deeply campanulate; lobes linear-lanceolate, 

 equalling the tube. Corolla yellow, with narrow petals. Pod coriaceous, oblong, 

 ovoid, rounded below, somewhat depressed above, one-celled, without a partial 

 partition or rarely with a rudimentary one; upper suture usually prominent. 



Pod with a rudimentary partition. 1. C. reventoides. 



Pod without a partition. 



Calyx densely black- villous. 2. C. reventus. 



Calyx not black-hairy or with a few scattered black hairs. 

 Calyx strigose with rather short hairs. 



Corolla yellow. 3. C. flavus. 



Corolla pinkish. 4. C. confertiflorus. 



Calyx silky-pilose or hirsute with long loose hairs. 



Corolla purple; calyx-teeth 4-5 mm. long. 5. C. argillosus. 



Corolla ochroleucous; calyx-teeth 2 mm. long. 6. C. urceolatus. 



1. C. reventoides (M. E. Jones) Rydb. Stems adsurgent or erect, 1-1.5 

 dm. high, canescent-strigose; leaflets 15-25, oval to oblong, 6-12 mm. long, sil- 

 very-strigose on both sides; raceme head-like, 3-4 cm. long; calyx black-hairy; 

 tube 4 mm. long; teeth 1 mm. long, obtuse; corolla yellowish, about 1 cm. long; 

 pod oblong-ovoid, 8-10 mm. long, 6 mm. thick. Astragalus reventoides Jones. 

 Dry hills and sage-brush flats: Mont. Plain. Je. 



2. C. reventus (A. Gray) Rydb. Stems 2-4 dm. high, numerous, sparingly 

 strigose; leaflets 21-37, oblong to linear, 1-1.5 cm. long, grayish strigose on both 

 sides or glabrate above; raceme short; calyx black-villous; tube 5 mm. long; 

 teeth subulate, 3 mm. long; corolla ochroleucous or whitish, nearly 2 cm. long; 

 pod ovate-oblong, glabrous, acute, 15-20 mm. long, 7-8 mm. wide, neither 

 suture very prominent. A. reventus A. Gray. Mountain sides: Wash. Ida. 

 Ore. Plain Submont. Ap-My. 



3. C. flavus (Nutt.) Rydb. Stems canescent-strigose, decumbent or ascend- 

 ing, 1-3 dm. high; leaflets 5-11, oblong to linear, grayish strigose beneath, 

 slightly strigose or glabrate above, 1-3 cm. long; raceme rather dense; calyx 

 strigose with white hairs; tube 4-5 mm. long; teeth subulate, about 2 mm. long; 

 corolla yellow, 10-12 mm. long; pod ovoid, strigose, 12-15 mm. long, sessile. 

 A. flavus Nutt. Dry plains: Wyo. N.M. Utah. Submont. Ap-My. 



4. C. confertiflorus (A. Gray) Rydb. Stems erect, 1.5-3 dm. high, canes- 

 cent-strigose; leaflets 11-13, narrowly linear, 15-25 mm. long; racemes 5-8 cm. 

 long; calyx strigose, with white hairs; tube scarcely 4 mm. long; teeth subulate, 

 2 mm. long; corolla pale lilac, 1 cm. long; keel tipped with purple; legume oval- 

 oblong, strigose, 10-12 mm. long. A. confertiflorus A. Gray. Dry places: Utah. 

 Son. 



5. C. argillosus (M. E. Jones) Rydb. Stems 1-2 dm. long, ascending, 

 canescent-strigose with long hairs; leaflets 9-13, narrowly linear to oblong- 

 linear, 1-2 cm. long; raceme short, dense; calyx silky-pilose with long hairs; 

 tube 4. mm. long; teeth subulate-filiform, 4-5 mm. long; corolla about 1 cm. long, 

 purplish; pod sessile, ovoid, obcompressed. A. argillosus M. E. Jones. Clayey 

 soil: Utah. Son. My. 



6. C. urceolatus (Greene) Rydb. Stems 3-4 dm. high, decumbent at the 

 base, sparingly strigose; leaflets 11-21, narrowly linear, 1-3 cm. long, 1-3 mm. 

 wide, sparingly strigose beneath, glabrate above; raceme short, head-like, densely- 

 flowered; calyx densely silky-hirsute; tube 5 mm. long; teeth subulate, 2 mm. 



