568 FABACEAE 



XIV. EUASTRAGALUS. 



Perennial or annual herbs; calyx campanulate to cylindric; corolla purple or white, rarely ochroleucous or 

 yellow; keel not beaked; pods ovoid to oblong, chartaceous, turgid, completely 2-celled. dehiscent; septum formed 

 by the intruded lower suture; seeds few to many. 



Plants perennial from woody rootstocks. 



Pods ascending or spreading; racemes densely flowered. 



Flowers deflexed or spreading in anthesis; lower suture of pod slightly sulcate; pods ellipsoid, spherical 



or nearly so in cross-section. 129. A. Mortonii. 

 Flowers erect in anthesis; lower suture deeply sulcate; pod ovoid, cordate or triangular in cross-section. 



Pod appressed-pubescent. 130. A. striatus. 

 Pod villous with spreading hairs. 



Stems glabrous or sparingly strigose. 131. A. goniatus. 

 Stems villous-pubescent. 



Corolla white; stems 2-5 dm. high. 132. A. Spaldingii. 



Corolla purple; stems less than 2 dm. high. 133. A. Austiniae. 



Pods deflexed, lenticular in outline; racemes loosely flowered, corolla white or ochroleucous. 



Racemes elongated, many-flowered, usually longer than the leaves. 134. A. Lyallii. 

 Racemes short, rather few-flowered, usually shorter than the leaves. 



Leaves and stems villous; pod abruptly acute. 135. A. lentiformis. 



Leaves and stems strigose; pod gradually acute. 136. A. Lemmonii. 



Plants annual; beak of the pod equaling the ovoid deeply sulcate body. 137. A. Breweri. 



XV. Hesperastragalus. 



Slender annuals, with distinct stipules; leaflets usually retuse; flowers subsessile in heads or short spikes, 

 usually crowded, small, rarely over 8 mm. long; calyx long-villous; pods didymous, distorted or transversely 

 rugose on the sides, 3-5 mm. long, ovoid to broader than long, coriaceous, not inflated, sessile, 2-celled. 



Pods little or not at all exserted beyond the calyx and not reflexed. 



Calyx white-hairy; pods deeply and narrowly grooved dorsally, the two lobes approximate, short-pubescent. 



138. A. dispermus. 



Calyx usually black-hairy; pods didymous, the two lobes diverging, minutely and rather sparsely strigose, 

 rarely glabrous. 139. A. didymocarpus. 



Pods well exserted and strongly reflexed-pubescent with spreading or sometimes appressed hairs. 



140. A. Gambellianus. 



1. Astragalus impensus (Sheldon) Woot. & Standi. Nevada Spiny Rattle-weed. 



Fig. 2775. 



Astragalus Kentrophyta var. elatus S. Wats. Bot. King. Expl. 77. 1871. 

 Astragalus viridus var. impensus Sheldon, Minn. Bot. Studies 1: 118. 1894. 

 Kentrophyta impensus Rydb. Bull. Torrey Club 32: 665. 1905. 

 Astragalus impensus Woot. & Standi. Contr. U.S. Nat. Herb. 19: 369. 1915. 

 Astragalus montanus var. impensus M. E. Jones, Rev. N. Amer. Astrag. 80. 1923. 



Perennial, diffusely branched from the base, the stems erect or ascending, 3-4 dm. high, 

 simple or with a few short branches. Stipules united only at the base, lanceolate, with elongated 

 spinulose tips; leaflets 5-7, subulate to linear-lanceolate, 8-15 mm. long, strongly ribbed, spinulose- 

 tipped. strigose ; flowers axiliary in clusters of 2 or 3 ; calyx-tube campanulate, 1 . 5 mm. long, the 

 teeth about 1 mm. long, subulate ; corolla ochroleucous, 4 mm. long ; banner oblong, reflexed ; keel 

 obtuse, shorter than the wings ; pod ovoid, flat, 6-7 mm. long, both sutures prominent, 1-2-seeded. 



Dry valleys, Upper Sonoran and Transition Zones; eastern Washington to western Colorado, south to 

 Nevada and Arizona. Type locality: "Holmes Creek Valley, Nevada." May-Sept. Spiny Milk Vetch. 



2. Astragalus tegetarius S. Wats. Alpine Spiny Rattleweed. Fig. 2776. 



Astragalus tegetarius S. Wats. Bot. King Expl. 76. 1871. 



Kentrophyta tegetaria Rydb. Bull. Torrey Club 34: 421. 1907. 



Astragalus montanus var. tegetarius M. E. Jones, Rev. N. Amer. Astrag. 81. 1923. 



Kentrophyta montana Jepson, Man. Fl. PI. Calif. 583. 1925. Not Nutt. 



Perennial, the stems scarcely 1 dm. long, diffusely spreading or decumbent. Stipules ovate, 

 scarious, 4-5 mm. long, united to near the middle ; leaflets 3-9, narrowly linear-lanceolate, rigid, 

 hirsutulose, 5-8 mm. long, spinulose-tipped ; peduncles 2-10 mm. long, 1-3-flowered ; calyx-tube 

 about 2.5 mm. long, the teeth subulate, 2 mm. long; corolla 5-6 mm. long; pod ovoid, 5 mm. 

 long, 2.5 mm. wide, compressed, hirsutulose. 



Boreal Zones; Idaho and Montana to Utah and Colorado, southward to eastern Oregon, Sierra Nevada, Cali- 

 fornia, and Nevada. Type locality: "Peaks of the East Humboldt and Clover Mountains, Nevada." July-Aug. 



3. Astragalus tegetarioides M. E. Jones. Blue Mountains Locoweed. Fig. 2777. 



Astragalus tegetarioides M. E. Jones, Contr. West. Bot. No. 10: 66. 1902. 



Cespitose perennial, the stems much branched forming dense mats, about 1 dm. long, the 

 whole plant silvery with wavy hairs. Leaves 2.5-4 cm. long, petiole filiform, elongated; leaflets 

 nearly contiguous, 5-7, obcordate, 4-5 mm. long, petiolulate, folded ; peduncles filiform, about 

 2 cm. long; flowers horizontal, usually 6 in the head; calyx-tube about 1 mm. long, the teeth 

 lax, 2 mm. long ; banner 3 mm. long, purple-striped, abruptly erect ; pod 4-5 mm. long, and 

 about 3 mm. high, chartaceous, flattened laterally but swollen over the solitary seed. 



Sandy soil, Arid Transition Zone; Blue Mountains, Oregon. Type locality: Buck Range, southern Blue 

 Mountains, Oregon. May-July. 



