488 MANUAL OF POISONOUS PLANTS 



Distribution. A very common weed along railroads, door yards, and 

 fields from Canada south to Florida and west to Illinois, Wisconsin, Minne- 

 sota, Missouri, Dakotas, Nebraska and Kansas, and Pacific North coast. Com- 

 mon hedge mustard is a naturalized weed from Europe. It occurs throughout 

 Europe, Russia, Germany, Great Britain, France— except Northern Scandinavia. 



Sisymbrium atlssimum L. Tumbling Mustard 



An erect, much branched annual from 1-4 feet high, lower leaves runci- 

 nate pinnatifid, irregular toothed or wavy margined; upper leaves smaller, thread- 

 like; after flowering, leaves drop, leaving the stem and pods; flowers pale 

 yellow, rather large; sepals 4, green; corolla of pale yellow petals; pods narrow- 

 ly linear, divergent; seeds small, longer than broad, generaly oblong in outline 

 with rather blunt ends ; radicle usually very prominent and straight, curved 

 spirally around the cotyledons. 



Distribution. This weed has spread with considerable rapidity in the 

 Northwest. Dr. Robinson states that it was once scarcely more than a bal- 

 last weed about the large cities of the Atlantic seaboard, and records its oc- 

 currence sparingly in southern Missouri (Bush). It is common now, however, 

 from the Mississippi Valley northwest to the Pacific Coast. One of the most 

 common weeds of Montana, Idaho, Eastern Washington, Oregon, and native to 

 British Columbia. Found also along the Atlantic seaboard. 



Poisonous properties. This plant has properties somewhat similar to those 

 described for Mustard; therefore may produce deep ulcers which are difficult to 

 heal. 



Brassica (Tourn.) L. Mustard, Turnip, Rape 



Annual or biennial branching herbs, basal leaves pinnatifid, flowers yellow, 

 racemose, pods elongated nearly terete or 4 sided; seeds spherical, 1 row 

 in each cell; cotyledons conduplicate. About 85 species of Europe, Asia, and 

 North Africa, introduced in North and Soutii America, Australia. The black 

 mustard (B. nigra) and charlock {B. arvensis) common in grain fields and 

 waste places across the continent. 



Brassica nigra Koch. Black Mustard 



A tall, coarse, much branched annual, 2-5 feet high; hairy or smoothish, 

 somewhat bristly, at least on the veins; leaves variously divided or deeply cut, 

 and sharp toothed; — large terminal lobe; the upper leaves small, simple, 

 usually linear; flowers yellow, smaller than in charlock; pods smooth, about yi 

 inch long, 4-cornered, tipped with a slender beak; seeds black or reddish brown, 

 smaller than in charlock; cotyledons conduplicate. 



Brassica arvensis (L.) Ktze. Mustard or English Charlock 



Branching annual from 1-3 feet high, hispid or glabrate; lower leaves 

 petioled with 1 large terminal lobe, and several small lateral lobes, with the 

 divisions unequal; upper leaves barely toothed; flowers yellow, large and very 

 fragrant; pods 1-2 inches long, irregular in outline, appearing somewhat nodose, 

 3-7 seeded, or more occasionally; the upper part of pod forms the beak; 

 seeds round, brownish black, darker than in B. nigra, and more minutely pitted. 

 When moistened, the seeds become mucilaginous. 



Distribution. It is a common and troublesome weed in cultivated ground 

 from Mass. to Oregon. The most troublesome weed in grain fields of the 

 Northwest. 



