inriati. 97 



greatly obcompressed and arched, bisulcate ventrally. 

 acuminate at both ends, dorsal suture a little intruded, 

 Pods arched, with sharp, raised ventral snture, 



acute at both ends. 77 Ikckwithii. 



2A. Pods triquetrous, partly 2-celled by the intrusion of the dorsal 

 suture very thin and papery and almost translucent, half-elliptical, 

 about 1.5 cm. long, sessile, reflexed in short racemes as are the 

 flowers. Flowers about 5 mm. long, short and broad. Slender 

 and low plants related to A. Geyeri. Triquetri. 



Annuals. 78 triquetrus. 



Perennials. 79 C'raigi. 



3A. Pods 2-celled or nearly so, by the intrusion of both sutures, in- 

 flated, not over 4 cm. long, normally papery, rarely coriaceous, 

 normally ovate, rarely globse or linear, always arcuate or very 

 oblique, not noticeably stipitate, jointed to calyx, mostly mottled, 

 apiculate to acuminate, ovate to oblate in cross section, broadest 

 and truncate at base or cordate there. Stipules small, not con- 

 nate. Flowers never cream-colored, very variable in size but 

 normally rather small, narrow and straight, not ovet 1-5 cm. long. 

 Calyx short-cylindric, with triangular teeth. Plants blooming in 

 early summer. 



Pods 2-celled. 80 lentiginosus. 



31. Astragalus pauclflorus. Hook. Fl. Bor. Am. 1 149 (1814). A. 

 vexilliflexus Sheklrn. Trrgacantha Kimtze. Pods .5-10 mm. long, about 

 3 mm. high, conspicuously laterally flattened except in the middle, 

 (the cross section elliptical), oblong to elliptical-oblong very shortly api- 

 culate at both ends, puherulent, reflexed, with both sutures prominent 

 and the ventral thick, not sulcate, convex on both sutures, or the ven- 

 tral suture rarely straight, puber.ilent and ashy, splitting from the base 

 through both sutures and valves falling apart, ventral suture only 

 thickened within, walls rather stiff. Flowers like those of A. montanus 

 but larger, 5-10 mm. long, .5-12, closely racemose, spreading to reflexed, 

 purple or white. Banner oval to rou"d, 4-S mm. long, abruptly bent 

 to erect at end of calyx, with sides reflexed about 1 mm. wide. Wings 

 mostly white, lanceolate, 1-2 mm. shorter than b-niier, much arched, 

 about as much longer than keel, purple-veined. Keel about 2 mm. long 

 and high, abruptly erect, the obliquely truncate, tip triangular, in- 

 curved more than 90 degrees. Calyx tube Hedeoma-like, nearly tur- 

 binate, about 2 mm. long, acute rnd oblioue at b^se, the subulate and 

 curved teeth fully as long as tube. Pedicels filiform, often twisted, 

 about 2-3 mm. long, as long as the delicate and subulate bracts. Leaves 

 with petiole about half the rachis. Leaflets oblong to lanceolate 

 or elliptical, acute, 3-4 mm. wide. 3-6 pairs. Stipules hyaline or black 

 below, 3-5 mm. long. Plants ashy with rough and flatfish hairs ab- 

 ruptly appressed. This grows with or near A. tenellus and can be sepa- 

 rated by the sessile pods, with ventral suture less arched, mostly pur- 

 ple flowers, long bracts, petioled leaves and relatively few leaflets. 

 From A. Wingatensis it is separable by its habitat, not spotted pods 

 and leaflets not linear, and congested habit. Rather common in moist 

 valleys along creeks from the bad lands of Nebraska and Dakotah 

 through Wyoming and northward and northwestward to the u]iper 

 Waters of the Missoula and British America, at least as far north as 

 the Cypress Hills. The flowers are often rather cleistogamous, and 

 then minute and white. This has the habit of the Debiles and connects 

 the two groups. 



