666 RYDBERG: ASTRAGALUS AND ITS SEGREGATES 
16. HOMALOBUS Nutt. in T. & G. Fl. N. Am. 1: 350. 
1838. 
The following are the Colorado species: H. caespitosus Nutt., 
H. wingatanus (S. Wats.) Rydb.; HY. Clementis Rydb., H. tenellus 
(Pursh) Britton, H. campestris Nutt., H. decurrens Rydb., #7. 
hylophilus Rydb., H. tenuifolius Nutt. and H. decumbens Nutt. 
Also: 
Homalobus grallator (S. Wats.) Rydb. 
Astragalus grallator S. Wats. Zoe 3: 52. 1892. 
Homalobus acerbus (Sheld.) Rydb, 
Astragalus acerbus Sheld., Bull. Geol. & Nat. Hist. Surv. Minn. 
©: 123. «1904. 
Homalobus junciformis (A. Nelson) Rydb. 
Astragalus junciformis A. Nelson, Bull. Torrey Club 26: 9. 
1899. 
Homalobus camporum Rydb. sp. nov. 
A cespitose perennial; stems erect, 1-2 dm. high, grayish- 
strigose ; leaves 3—5 cm. long; leaflets g—-15, linear to nearly fili- 
form, rarely oblong, 4-10 mm. long, 0.5—2 mm. wide, silvery- 
canescent ; stipules ovate, somewhat scarious, strigose; raceme 
5-10 cm. long; flowers 7-15; bracts subulate; calyx campanu- 
late, white-silky, about 3 mm. long; lobes lance-subulate, about 
%, as long as the tube; banner about 6 mm. long, white or ochro- 
leucous with purple veins; keel with a narrow purple tip; pod 
linear, 12-18 mm. long, 2-3 mm. wide, compressed, straight, 
strigose. 
This is rather common on the plains and hills from Alberta to 
Colorado and Utah and has been known as Astragalus cam- 
pestris, A. decumbens and A. tenuifolius Nutt. The first of these is 
ataller plant 3-4 dm. high, more simple; its pod is 2~—2.5 cm. 
long and its keel is broad and blunt. A. decumbens has an 
arcuate pod and in H. tenuzfolius the calyx-teeth are triangular 
and only 4%—¥% as longasthetube. As the type may be assigned : 
Wyominc : Bush Ranch, Sweetwater Co., June 10, 1900, Aven 
Nelson 7085. 
Homalobus flexuosus (Hook.) Rydb. 
Phaca flexuosa Hook. Fl. Bor. Am. 1: 141. 1831. 
Astragalus flexuosus Dougl.; Hook. Joc. cit., as a synonym. 
