(MUSTARD FAMILY.) 37 



cemes corymbose-branched; pods hairy, oval-oblong or lanceolate (2" -5" long), 

 on slender pedicels, tipped with a long style. Cliffs, Harper's Ferry, Natural 

 Bridge, &c., Virginia, to Kentucky River, and southward. April, May. 



2 D. aiMibisans, Michx. Slightly pubescent ; flowering stems (6' -10 

 high) erect and mostly simple; leaves oblong-lanceolate, linear, or the lower spatu- 

 late, spariny'ty toothed; racemes short, usually simple; pods glabrous, oblong- 

 lanceolate (5" -6" long), on rather short pedicels, tipped with a very short style. 

 Rocky banks, Vermont, Northern New York, Upper Michigan, and north- 

 ward. May, June. Petals large. 



* * Annual or biennial : leafy stems short : flowers white or in No. 4 yellow : style 

 none. (Leaves oblong or obovate, hairy, sessile.) 



3. D. bracliycarpa, Nutt. Low (2' -4' high), minutely pubescent, 

 stems leafy to the base of the dense, at length elongated raceme ;' leaves narrowly 

 oblong or the lowest ovate (2^"-4" long), few-toothed or entire ; flowers small ; 

 pods smooth, narrowly oblong, acutlsh (2" long), about the length of the ascending 

 pedicels. Dry hills, Illinois, Kentucky, and southward. April. 



4. D. nemorosa, L. Leaves oblong or somewhat lanceolate, more 

 or less toothed ; racemes elongated (4'- 8' long in fruit) ; petals cmarginate, small ; 

 pods elliptical-oblong, half the length of the horizontally spreading pedicels, pubescent 

 (D. nemoralis, Ehrh.), or smooth (D. lutea, DC.). Fort Gratiot, Michigan, 

 and northward. (Eu.) 



5. D. cimeifoiia, Nutt. Leaves obovate, wedge-shaped, or the lowest 

 spatulate, toothed; raceme somewhat elongated in fruit (l'-3'), at length equal- 

 ling the naked peduncle ; petals emarginate, much longer than the calyx ; pods 

 obi ou (j -linear, minutely hairy t longer than the horizontal pedicels. Grassy places, 

 Illinois, Kentucky, and southward. March, April. 



6. D. Caroliniatia, Walt. Small (l'-4' high); leaves obovate, most- 

 ly entire ; peduncles scape-like ; petals twice the length of the calyx ; raceme 

 short or corymbose in fruit ('-!' long) ; pods broadly linear, smooth, much longer 

 than the ascending pedicels. Sandy fields, Rhode Island to Illinois, and 

 southward. March - June. 



7. I>. micrtntlia, Nutt. Pods minutely hairy ; flowers small or minute; 

 raceme sometimes elongated ; otherwise as in No. 6, of which Mr. Bebb proves 

 it to be a variety. From Wisconsin southwestward. 



$ 2. ER6PHILA, DC. Petals 2-cleft. (Annual or biennial: flowers white.) 



8. D. vcrna, L. (WHITLOW-GRASS.) Small (scapes l'-3'high) ; leaves 

 all radical, oblong or lanceolate ; racemes elongated in fruit ; pods varying from 

 round-oval to oblong-lanceolate, smooth, shorter than the pedicels. Sandy 

 waste places and road-sides : not common. April, May. Not found north of 

 Lower Canada. The same as the plant of Europe, and perhaps introduced. 

 (Eu.) 



13. VESICAR1A, Lam. BLADDER-POD. 

 Pouch globular and inflated, or more or less flattened parallel to the orbicular 

 partition ; the hemispherical or convex thin valves nerveless. Seeds few or ec v- 



