PAPILIONACEAE. {Vor. II 
2. Homalobus montanus (Nutt.) Britton. 
Prickly Milk Vetch. (Fig. 2152.) 
Kentrophyla montana Nutt.; T. & G. Fl. N. A. 1:353. 1838. 
Kentrophyta viridis Nutt.; T. & G. Fl. N. A. 1: 353. 1838. 
Bi id Kentrophyla A. Gray, Proc. Acad. Phil. 1863: 
. 1863. 
Densely tufted, intricately branched, 2/-10’ high, 
finely canescent. Stipules linear-lanceolate, spiny- 
tipped, 2’’-5’’ long; leaflets 3-7, linear, rigid, spiny, 
widely spreading, 3/’-6’’ long, %4’’ wide; flowers 1-4 
together in the axils, nearly sessile, yellowish-white or 
bluish-tinged, 2’”-3’’ long; pod sessile or very short- 
stalked, 1-3-seeded, ovoid-oblong, acute, coriaceous, 
dehiscent,’ pubescent, 3//-4/’ long. 
In dry, rocky places, Nebraska to New Mexico, Nevada 
and the Northwest Territory. June-Sept. 
3. Homalobus caespitoésus Nutt. ‘Tufted 
Milk Vetch. (Fig. 2153.) 
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 ob- 
long-linear leaflets; peduncles scapiform, exceeding or 
equalling the leaves; flowers purple, 4/’—5’’ 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 and Colorado, north to the 
Northwest Territory. May-July. 
26. OROPHACA Britton. 
Perennial, silvery or villous-pubescent low tufted herbs, with branched woody caudices, 
deep roots, membranous scarious stipules, sheathing and united below, and digitately 
3-foliolate (rarely 5-foliolate) leaves, resembling those of Lupines. Flowers few, capitate or 
racemose, the clusters sessile or peduncled. Keel of the corolla blunt. Pod coriaceous, 
completely 1-celled, ovoid or oval, few-seeded, villous, partly or wholly enclosed by the calyx. 
[Greek, mountain vetch. ] 
Three known species, the following, and one in Colorado and Wyoming. 
Flowers yellowish, 1-3 together in the axils. 1. O. caespitosa. 
Flowers blue-purple, in peduncled racemes. 2. O. sericea. 
1. Orophaca caespitosa (Nutt.) Britton. Sessile-flowered Milk Vetch. 
(Fig. 2154.) 
Astragalus triphyllus Pursh, Fl. Am. Sept. 740. 1814. Not 
Pall. 1800. 
Phaca caespitosa Nutt. Gen. 2:98. 1818. 
Phaca argophylia Nutt.; T. & G. Fl. N. A. 1: 342. — 1838. 
A, hyalinus M.E. Jones, Proc. Cal. Acad. (II.) 648. 1895. 
Silvery-canescent, densely tufted from a deep root, 
2/-4’ high. Stipules scarious, imbricated, glabrous, 
ovate-lanceolate, 3/’-4’’ long; leaves digitately 3-5- 
foliolate, slender-petioled; leaflets oblong or oblanceo- 
late, acute or obtusish at the apex, narrowed or cuneate 
at the base, 6’’-8’” long; flowers yellowish, 6//-8’” 
long, sessile in the axils of the leaves; pod 1-celled, 
sessile, ovoid, acute or acuminate, coriaceous, dehiscent, 
villous-pubescent, enclosed by the calyx, 2/’-3’” long. 
Prairies, Nebraska and South Dakota to Montana and the 
Northwest Territory. May-July. 
