Dicotyledones. 49 



i. Lepidium Virginicum, L. WILD PEPPERGRASS. Pods slightly winged 

 above, orbicular or oval, about j^inch broad. Petals usually present. Basal leaves 

 from spatulate to obovate, somewhat pinnatifid. Stem leaves sessile, lanceolate or 

 linear, entire or dentate. Pedicels slender and spreading, from | to inch long in 

 fruit. Roadsides and fields. 



II. SISYMBRIUM. fledge Mustard. 



(Ancient Greek name for a plant of this family.) 



Flowers mostly white or yellow. Seeds usually in only i row in 

 each cell of the elongated terete or angled siliques, sometimes 2-rowed ; 

 valves i-3-nerved. Mostly tall and erect annuals and perennials. 

 Leaves simple, entire, lobed, or pinnatifid. 



1. Sisymbrium officinale, Scop. (L., officina, a workshop.) HEDGE MUSTARD. 

 Leaves runcinate-pinnatifid. Flowers yellow; pods linear, about 5 inch long, 

 appressed. In waste places. 



2. Sisymbrium canescens, Nutt. (L., canescens, becoming white.) TANSY 

 MUSTARD. Leaves 2-pinnatifid, frequently hoary or downy. Flowers very small 

 and yellowish. Pods oblong-club-shaped or oblong-linear, shorter than the nearly 

 horizontal pedicels. Seeds in 2 rows in each cell. In waste places. 



3. Sisymbrium Thaliana, Gaud. (Gr., thaleia, blooming.) MOUSE-EAR 

 CRESS. Leaves obovate or oblong, entire or barely toothed. Flowers white. 

 Pods linear and somewhat 4-sided, longer than the spreading pedicels. Slender 

 and branching ; about 9 inches tall. Old fields and waste places. 



III. BRASSICA. 



(Latin name for cabbage.) 



Flowers showy and yellow in elongated racemes. Siliques sessile, 

 elongated, terete or 4-sided, tipped with a more or less elongated beak ; 

 the convex valves i-5-nerved. Seeds in i row in each cell. Erect, 

 branching, herbaceous annuals, biennials, or perennials, with basal 

 leaves pinnatifid and stem leaves dentate or nearly entire. 



1. Brassica nigra, Koch. (L., niger, black.) BLACK MUSTARD. Pods from 

 \ to i inch long, slender, and appressed. Flowers bright yellow, from 4 to nearly 

 5 inch broad. From 2 to 7 feet high. Lower leaves slender-petioled, pinnatifid, 

 with a large, terminal lobe, the lobes dentate ; the upper leaves much smaller, entire, 

 and lanceolate, or oblong. Brassica juncea, Cosson., has slender, erect pods, from 

 i to 2 inches long, on slender pedicels, and runcinate-pinnatifid lower leaves. 

 Brassica sinapistrum, Boiss., has spreading or ascending pods from 5 to f inch 

 long, somewhat constricted between the seeds, on stout pedicels not more than 

 \ inch long in fruit. In fields and waste places. 



2. Brassica campestris, Linn. (L. campestris, pertaining to a level field.) 

 RUTA-BAGA or SWEDISH TURNIP. Flowers creamy yellow ; roots tuberous. In 

 cultivated grounds. 



