HOFFMANN: FLORA OF BERKSHIRE COUNTY. 289 



APIOS. Ground-nut. 

 {Glycine 111. Fl. ed. 2.) 



A. tuberosa Moench. Ground-nut. — (G. Apios 111. Fl. ed. 2.) 

 Alluvial thickets and rich damp upland ; frequent in the valley. 



BAPTISIA. False Indigo. 



B. tinctoria (L.) R. Br. Wild Indigo.— Sandy soil in open 

 woods; common in the southern part of the valley. 



CASSIA. Senna. 



C. marilandica L. Wild Senna. — Roadsides in low ground; 

 occasional in the southern part of the valley. West Stockbridge; 

 Egremont; Sheffield. 



CORONILLA. 



C. VARiA L. — Occasionally established along roadside banks in the 

 valley. 



CROTALARIA. Rattle-box. 



C. sagittalis L. Rattle-box. — Sand-plain, Sheffield. 



DESMODIUM. Tick Trefoil. 

 {Meibomia 111. Fl. ed. 2.) 



Key to Desmodium. 



1. Plant prostrate D. roiundifolium. 



2. Plant erect. 



a. Pod raised on a stalk many times lonjier tlian tlie slightly toothed 

 calyx. 

 Leaves all crowded at tiic summit of sterile stems. . .1). uwiijlnrum. 

 Leaves all crowded at the summit of the stem from which ari.se.s the 



elongated panicle I J. grandijlorum. 



a'. Pod raised on a stalk little if at all surpassing the deeply cleft calyx. 

 b. Stipules conspicuous and persistent; flowers rather large; stem 



smooth I). hnicU'osum. 



h'. Stipules mostly dcciiluous, sm.all and inconspicuous. 

 c. I'iowcrs middle-sized, not very sliowy. 



St(>m i)ul)escent; leaflets softly and lim-ly pubescent. 



/). DilU'Hii. 



Stem smooth; leaflets smooth D. paniciilatum. 



c'. Flowers 8 to 12 mm. long, showy; stem h:iiry I), canadcnse. 



