386 



FABACEAE. 



VOL. II. 



3. Phaca longifolia (Pursh) Nutt. Long-leaved Milk Vetch. Fig. 2555. 



Psoralea longifolia Pursh, Fl. Am. Sept. 741. 1814. 

 Phaca longifolia Nutt. ; T. & G. Fl. N. A. i : 346. 1838. 

 Astragalus pictus var. filifolius A. Gray, Proc. Am. Acad. 6 : 



215. 1864. 

 A. filifolius Smyth, Trans. Kans. Acad. 15: 61. 1895. 



Erect, very slender, branching, finely canescent, 6'-i8' 

 high. Stipules subulate, rigid, those of the lower part of 

 the stem connate; leaflet usually i, narrowly linear, nearly 

 terete, i'-4' long, i"-i" wide, sometimes 3 or 5; leaves 

 persistent ; flowers few, pink, 3 "-5" long, in short loose 

 racemes ; peduncles much shorter than the leaves ; pod 

 i -celled, short-stalked, much-inflated, membranous, spotted, 

 glabrous, ovoid, short-pointed, not furrowed, about i' long, 

 1' thick. 



In sandy soil, South Dakota to Nebraska, Wyoming, Idaho 

 and New Mexico. Bird-egg pea. May-June. 



Phaca Bodini (Sheldon) Rydb., a decumbent species with 

 small blackish pubescent pods and purple flowers, common in 

 Wyoming and Colorado, enters our area in western Nebraska. 



28. HOMALOBUS Nutt; T. & G. Fl. N. A. i : 352. 1838. 



Perennial herbs, with pinnate simple or pinnately 3-5-foliolate leaves, and racemose 

 mostly small flowers, the peduncles short, or elongated. Keel of the corolla obtuse. Pod flat, 

 glabrous or pubescent, completely i-celled, few-several-seeded, the sutures both prominent 

 externally. [Greek, regular-lobes.] 



Besides the following species, some 30 others occur in western North America. Type species : 

 Homalobus caespitosus Nutt. 



Plants leafy-stemmed ; leaves pinnate; leaflets 9-23, thin. i. H. tenellns. 



Plants scapose ; leaves simple, or pinnately 3-s-foliolate, the leaflets very narrow. 2. H. caespitosus. 



i. Homalobus tenellus (Pursh) Britton. Loose- 

 flowered Milk Vetch. Fig. 2556. 



'Astragalus tenellus Pursh, Fl. Am. Sept. 473. 1814. 

 Ervum multiflorum Pursh, Fl. Am. Sept. 739. 1814. 

 Homalobus inultiflorus T. & G. Fl. N. A! I : 351. 1838. 

 A. inultiflorus A. Gray. Proc. Am. Acad. 6: 226. 1864. 

 H. stipitatus Rydb. Bull. Torr. Club 34: 419. 1907. 



Ascending or diffuse, slender, branched, finely pubes- 

 cent, or glabrate, io'-i8' high. Stipules broadly ovate, 

 i i"-3" long, acute or obtuse, the upper ones connate; 

 leaflets 9-23, thin, oblong, linear-oblong or oblanceo- 

 late, obtuse at the apex, narrowed at the base, 6"-io" 

 long; flowers yellowish-white, 3"-4" long; in loose 

 spike-like racemes; pod stalked, straight, oblong, acute 

 at each end, papery, glabrous, 6"-8 ' long, 2" wide. 



Dry soil, Minnesota to Nebraska, Colorado, north to Sas- 

 katchewan and British Columbia. May-Aug. 



2. Homalobus caespitosus Nutt. Tufted Milk 



Vetch. Fig. 2557. 



Homalobus caespitosus Nutt. ; T. & G. Fl. N. A. i : 352. 1838. 

 Astragalus caespitosus A. Gray, Proc. Am. Acad. 6: 230. 1864. 



Silvery-canescent, much tufted from a deep root, 3'-6' 

 high. Stipules scarious, much imbricated, lanceolate, acu- 

 minate, 4"-6" long; leaves simple, spatulate-linear, acute, 

 i'-2' long, or some of them 3-5-foliolate, with oblong- 

 linear leaflets ; peduncles scapiform, exceeding or equalling 

 the leaves ; flowers purple, 4"-s" long, in heads or short 

 spike-like racemes ; pod erect, sessile, few-seeded, oblong, 

 acute, coriaceous, slightly curved, pubescent, 4"-5" long; 

 calyx-teeth subulate. 



In dry rocky soil, Nebraska to Colorado, Utah, North Da- 

 kota and Assiniboia. May-July. 



