570 FABACEAE 



4. Astragalus strigdsus Coult. & Fisher. Gray-haired Locoweed. Fig. 2778. 



Astragalus strigosus Coult. & Fisher, Bot. Gaz. 18: 299. 1893. 

 Astragalus griseopubescens Sheldon, Minn. Bot. Studies 1 : 24. 1894. 

 Homalobus strigosus Rydb. Bull. Torrey Club 40: 53. 1913. 



Perennial, the stems several, decumbent or ascending, 15-35 cm. high, strigose. Leaves 3-8 

 cm. long; leaflets 13-21, linear to narrowly linear, 1-2 cm. long, strigose and cinereous on both 

 surfaces; racemes lax, 10-20-flowered ; calyx-tube 2.5 mm. long, black-hairy, the teeth subulate, 

 about equaling the tube ; corolla purplish, about 10 mm. long ; keel merely obtuse at tip and dark 

 purple; pods sessile, linear, 15-20 mm. long, about 3 mm, deep, strigose. 



Dry plains and ridges, Upper Sonoran and Transition Zones; eastern Washington to Montana. Type lo- 

 cality: Basin, Montana. June— July. 



5. Astragalus serotinus A. Gray. Late-flowering Rattle-weed. Fig. 2779. 



Astragalus serotinus A. Gray, Pacif. R. Rep. 12: 51. pi. 5. 1860. 



Homalobus serotinus Rydb. Mem. N.Y. Bot. Gard. 1 : 248. 1900. 



Phaca serotina Piper, Contr. U.S. Nat. Herb. 11: 374. 1906. 



Astragalus campestris var. serotinus M. E. Jones, Rev. N. Amer. Astrag. 75. 1923. 



Perennial, the stems several, ascending or erect, slender, 2-4 dm. high, strigose. Leaves 8-15 

 cm. long; leaflets 9-21, linear to linear-lanceolate, glabrous above, strigose beneath, 1-3 cm. long; 

 peduncles slender ; racemes lax, 5-15-flowered ; flowers spreading, purplish ; calyx-tube about 

 2.5 mm. long, black-hairy; teeth subulate, less than 1 mm. long; corolla 6-8 mm. long; keel 

 with a deep purple broad obtuse tip; pod linear, 20-25 mm. long, about 3 mm. deep, mainly 

 strigose or glabrate in age. 



Open pine forests. Arid Transition Zone; British Columbia and eastern Washington as far south as Walla 

 Walla, to Montana. Type locality: "On the Okanogan near the Columbia River." May-July. 



Astragalus serotinus var. Palliseri (A. Gray) J. F. Macbride, Contr. Gray Herb. 65: 37. 1922. (As- 

 tragalus Palliseri A. Gray, Proc. Amer. Acad. 6: 227. 1864.) Pod glabrous from the beginning, otherwise 

 closely resembling the typical form of the species_ which has the pods strigose, at least when young. Columbia 

 Basin region of southeastern Washington and adjacent Oregon. 



6. Astragalus stenophyllus Torr. & Gray. Narrow-leaved Locoweed. Fig. 2780. 



Astragalus leptophyllus Nutt. Journ. Acad. Phila. 7: 18. 1834. Not Desf. 1800. 

 Astragalus stenophyllus Torr. & Gray, Fl. N. Amer. 1 : 329. 1838. 

 Homalobus stenophyllus Rydb. Mem. N.Y. Bot. Gard. 1 : 249. 1900. 

 Phaca stenophylla Piper, Contr. U.S. Nat. Herb. 11: 371. 1906. 



Perennial, usually much branched from the somewhat woody base, the stems slender and 

 wiry, erect or ascending, 3-6 dm. high, glabrous or nearly so. Leaves 5-10 cm. long ; leaflets 

 mostly 9-13, rather distant, filiform to narrowly linear, 5-15 mm. long, sparsely strigose; pe- 

 duncles well exceeding the leaves ; flowers in a loose raceme, nodding ; calyx campanulate, 5 mm. 

 long, the teeth very minute ; corolla ochroleucous, 10-12 mm. long ; body of pod linear-oblong, 

 20-25 mm. long, 4-5 mm. deep, only slightly inflated in age, abruptly acutish at apex, narrowed 

 at base to a filiform stipe, 5-10 mm. long. 



Sagebrush plains and hillsides, Upper Sonoran and Arid Transition Zones; British Columbia to western 

 Montana south, east of the Cascades, to northeastern California and northern Nevada. Type locality: "Head- 

 waters of the Missouri." May— July. 



7. Astragalus MacGregorii (Rydb.) Tidestrom. MacGregor's Rattle-weed. 



Fig. 2781. 



Homalobus MacGregorii Rydb. Bull. Torrey Club 50 : 270. 1923. 

 Astragalus filipes var. residuus Jepson, Man. Fl. PI. Calif. 571. 1925. 

 Astragalus MacGregorii Tidestrom, Proc. Biol. Soc. Wash. 50: 20. 1937. 



Perennial, the branches several from the woody base, erect or ascending, slender, 4-6 dm. 

 high, glaucous, green and somewhat cinereous with a strigose pubescence. Stipules triangular- 

 subulate, erect, thin, about 3 mm. long; leaves 5-7 cm. long; leaflets about 13, linear, 8-15 mm. 

 long, 1 . 5-3 mm. wide, rounded or retuse at the apex, distinctly petiolulate, gray-green and 

 strigose ; peduncles often 10 cm. long ; racemes loosely flowered ; flowers pedicellate, spreading 

 or recurved; calyx-tube campanulate, 4-5 mm. long, very thin, the teeth triangular, scarcely 

 1 mm. long ; corolla ochroleucous, about 12 mm. long, the banner well exceeding the keel ; pod 

 linear-oblong, approximately of equal width throughout, rather abruptly acute at both ends- 

 20-25 mm. long, about 4 mm. wide, glabrous ; stipe filiform, 8-10 mm. long. 



Desert slopes, Sonoran Zones; southern California, from Mount Pinos to the Santa Rosa Mountains. Type 

 locality: near the Frazier Borax Mine, Mount Pinos, California. April-May. 



8. Astragalus filipes Torr. Thread-leaved Locoweed. Fig. 2782. 



Astragalus filipes Torr. ex A. Gray, Proc. Amer. Acad. 6: 226. 1864. 

 Tragacantha filipes Kuntze, Rev. Gen. PI. 944. 1891. 

 Homalobus filipes Heller, Muhlenbergia 9: 67. 1913. 



Stems slender, branched, 3-10 dm. long, strigose, from a cespitose caudex. Leaflets 7-11, nar- 

 rowly linear to filiform, 8-15 mm. long, strigose, acute; raceme lax, including the peduncle 1-2 

 dm. long; calyx -tube 3 mm. long, strigose, the teeth deltoid, 1 mm. long; corolla white, 8 mm. 



