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.

1.

H. tenellus.

Plants scapose; leaves simple, or pinnately 3-5-foliolate, the leaflets very narrow.

2.

H. caespitosus.

1. Homalobus Tenéllus (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 multiflorits T. & G. Fl. N. A. 1: 351. 1838. A. multiflorus A. Gray, Proc. Am. Acad. 6: 226. 1864. H. stipitatus Rydb. Bull. Torr. Club 34: 419. 1907.

Ascending or diffuse, slender, branched, finely pubescent, or glabrate, io'-i8' high. Stipules broadly ovate, 1/2"-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"-10" 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 Saskatchewan and British Columbia. May-Aug.

1 Homalobus Ten Llus Pursh Britton Loose Flowered  8981 Homalobus Ten Llus Pursh Britton Loose Flowered  899

2. Homalobus Caespitòsus Nutt. Tufted Milk Vetch

Fig. 2557

Homalobus caespitosus Nutt.; T. & G. Fl. N. A. 1: 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, acuminate, 4"-6" long; leaves simple, spatulate-linear, acute, 1'-2' long, or some of them 3-5-foliolate, with oblong-linear leaflets; peduncles scapiform, exceeding or equalling the leaves; flowers purple, 4"-$" 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 Dakota and Assiniboia. May-July.