237 



larcocarpi. 



in most herbarium specimens, but still globose when maturing nat- 

 urally, herbarium material is greatly and coarsely wrinkled mostly, 

 about 2.5 cm. long and 1.5 cm. wide, sulcate at both sutures when 

 fresh and very shortly mucronate-beaked, green to reddish. Flow- 

 ers normally bluish-purple but often nearly white, with elongated 

 banner and wings, rather loosely racemose-spicate, about horizontal. 

 Banner ovate to oblong-ovate, nearly 1.5 cm. long, deeply notched, 

 with sides very much reflexed so that it seems almost linear, abruptly 

 arched at end of calyx tube to 45". Wings elongated, about 1 cm. 

 long and 3 mm. wide, slightly ascending, very oblique at the notched 

 tip, narrower above, mostly white, much longer than keel. Keel 

 straight, about 5 mm. long, the tip abruptly arched to erect and 3 

 mm. high, very broad, the corner about square, purple. Calyx black- 

 ish with rather sparse and very short and closely appressed hairs, 

 the teeth very variable but mostly 2-4 mm. long and triangular. 

 Bracts twice the rather long pedicels in flower and about as long in 

 fruit. Peduncles from much shorter than, to as long as the leaves. 

 Spikes 5-10 cm. long and rather close. Leaves 1-1.5 dm. long when 

 fully developed above, the lower ones much reduced, ashy to smooth. 

 Leaflets 8-12 pairs, narrowly to broadly elliptical, the lowest often 

 oval, 1-1.5 cm. long. Stipules ovate. Stems about a foot long, 

 weak and widely spreading. Pubescence ashy to almost none, espe- 

 cially on the stems and pods, of short and flat appressed hairs. Com- 

 mon on sweet soil on the prairies from northern Texas to the base 

 of the Rockies and northward to the Saskatchewan, not on the 

 Snake river drainage, but on the Laramie Plains, and on the Pacific 

 slope along the tablelands of the head waters of the Missoula in 

 Deer Lodge Valley, eastward to eastern Iowa and Minnesota, Middle 

 Temperate life zone, and descending a little into the Lower Tem- 

 perate at the south. In early days the fruit was eaten by voyagers 

 and called Pomme du Prairie. When the fruit matures naturally 

 it becomes very cellular between the inner and outer skins and very 

 light and is easily blown about by the winds. It does not open at 

 maturity but gradually falls apart by decay. Its cellular character 

 is like that of A. pygmaeus and Musiniensis of the Navajo Basin. 



Astragalus crassicarpus vsr. pachycarpus (T. & G.) JoneS Cont. 

 8 17 (1898). A. pachycarpus T. & G. Fl. 1 332 (1838). This is a 

 southern form with pods round to oblong or ovate, decidedly obcom- 

 pressed. Flowers narrower and slender, whitish, about 1.5 cm. long. 

 Calyx smooth or nearly so. Bracts subulate and smaller. Pedicels 

 slender. Peduncles much shorter than the leaves. Leaves very nar- 

 row. Leaflets 11-16 pairs, rather long-petiolulate often oblanceo- 

 late, about 1 cm. long. Stipules rather short and narrow. Stems 

 slender, 1-2 ft. long. Nearly smooth throughout. This is the form 

 mostly of Missouri to Texas. The pods vary greatly from decidedly 

 oblique with the mucro above the middle to plum-shaped. 



197. Astragalus Mexicanus A. DC. PL Ear. Gen. 4 16 t 3 

 (1826). A. trichocalyx Nutt. Geoprumnon Rydberg. Pods about 

 as in A. crassicarpus. Flowers cream-white. Calyx white and woolly 

 with long hairs, almost sessile and with long bracts, teeth v.ery short. 

 Banner about 1 cm. long, ovate, with sides reflexed below and seem- 

 ingly triangular. Wings almost straight, a little longer than the 

 keel, oblique. Keel as in A. crassicarpus. Flowers very short-spi- 

 cate, the clusters rarely 5 cm. long. Leaves as in A. crassicarpus 

 but nearly smooth. Peduncles often as long as the leaves, not 

 short. Plants 1-2 ft. high, rather stout. Missouri to Texas and 

 southern Nebraska, on prairies eastward to Illinois. Lower Tem- 

 perate life zone. 



198. Astragalus Plattensis Nutt. in T. & G. Fl. 1 132 (1838). 

 Geoprumnon Rydberg. Pods about 1.5 cm. long, oval ovate, 6-8 

 mm. wide, and about 4 mm. high, conspicuously obcompressed and 

 sulcate ventrally, straight but decidedly oblique by the ventral suture 



