CRUCIFER^E. (MUSTARD FAMILY.) 35 



and broadish pods spreading or ascending. Fort Gratiot, &c., Michigan. 

 Boot-leaves hairy. Pod 1' long. Flowers pale purple. 



8. BARB A RE A, R. Br. WINTER CRESS. 



Pod linear, terete or somewhat 4-sided ; the valves being keeled by a mid- 

 nerve. Seeds in a single row in each cell, marginlcss. Cotyledons accumbent. 



Mostly biennials: flowers yellow. (Anciently called The Herb of St. Bar- 

 bara.) 



1. B. viilgftris, R. Br. (COMMON WINTER CRESS. YELLOW ROCK 

 ET.) Smooth ; lower leaves lyrate, the terminal division round ; upper leaves 

 obovate, cut-toothed, or pinnatifid at the base; pods convex-4-angled, much 

 thicker than the pedicel, erect, pointed with a manifest style; or, in the var. 

 STRfcTA, rather flatter, tipped with a thicker and very short style (B. prsecox. 

 Hook. FL Bor.-Am., &c.) ; or, in var. ARCUATA, ascending on spreading ped- 

 icels when young. Low grounds and road-sides. May. Probably naturalized 

 from Europe. But the varieties here indicated are indigenous from Lake Supe- 

 rior northward and westward. (Eu.) 



B. PRJECOX, R. Br. (B. patula, Fries), occasionally cultivated for salad 

 in the Middle States, under the name of Scurvy -Grass, is becoming spon- 

 taneous farther south. It is readily known by its longer and less erect pods, 

 scarcely thicker than their pedicels, and by the linear-oblong lobes of most of 

 the stem-leaves. 



9. ERYSOIUUI, L. TREACLE MUSTARD. 



Pod linear, 4-sided ; the -valves keeled with a strong midrib. Seeds in a single 

 row in each cell, oblong, marginlcss. Cotyledons (often obliquely) incumbent. 

 Calyx erect. Chiefly biennials, with yellow flowers ; the leaves not clasping. 

 (Name from e'pvco, to draw blisters.) 



I.E. clieirajritlioides, L. (WORM-SEED MUSTARD.) Minutely 

 roughish, branching, slender ; leaves lanceolate, scarcely toothed ; flowers small ; 

 pods small and short (7" -12" long), very obtusely angled, ascending on slender 

 divergent pedicels. Banks of streams, New York, Perm., Illinois, and north- 

 ward : apparently truly indigenous. July. (Eu.) 



2. E. Arkansamun, Nutt. (WESTERN WALL-FLOWER.) Minutely 

 roughish-hoary ; stem simple ; leaves lanceolate, somewhat toothed ; pods nearly 

 erect on very short pedicels, elongated (3' -4' long), exactly 4-sided ; stigma 2-lobed. 



Ohio (on limestone cliffs) to Illinois, and southwestward. June, July. 

 Plant stout, 1 - 2 high ; the crowded bright orange-yellow flowers as large as 

 those of the Wall-flower. 



10. SISYMBRIUM, L. HEDGE MUSTARD. 



Pod terete, flattish, or 4 - 6-sided ; the valves 1 - 3-nerved. Seeds oblong, 

 marginlcss. Cotyledons incumbent. Calyx open. Flowers small, white or 

 yellow. (An ancient Greek name for some plant of this family. ) 



