CRUCIFERAE. 175 



Brassica campestris L. Turnip. Smooth or nearly so, often glaucous, 

 30-90 cm. high; lower leaves petioled, somewhat lobed or toothed; upper entire 

 or nearly so, sessile and clasping by auricled bases; flowers yellow; pedicels 

 spreading; petals 6-10 mm. long; pods terete, 3-5 cm. long, narrowed into a 

 beak about 1 cm. long. 



A weed in fields. A cultivated form of this plant is the rutabaga. 



Brassica nigra (L.) Koch. Black Mustard. Erect, 30-80 cm. high, sparsely 

 hirsute; leaves green, slender-petioled, the terminal lobe large and coarsely 

 toothed, the few lateral lobes small; pods 15-18 mm. long, erect, on very short 

 pedicels, only the lower fourth seed-bearing; seeds dark-colored. 



In waste places. 



Brassica arvensis (L.) Kuntze. Charlock. Stout, annual, 30-90 cm. high, 

 hispid with scattered hairs; lower leaves pinnately parted, consisting of a 

 large ovate-oblong terminal segment and 1 or 2 pairs of much smaller ones, 

 all dentate; uppermost leaves sessile, none clasping; pods 2-4 cm. long, erect or 

 ascending, the fertile portion torulose, tipped with a flat and stout beak half 

 as long. 



A weed in waste ground. 



Brassica juncea (L.) Cosson. Stout, 30-100 cm. high, the herbage some- 

 what glaucous and nearly glabrous; basal leaves lyrately lobed; cauline oblong, 

 entire or nearly so, narrowed at base and short-petiolate; pods spreading, 

 terete, 2.5-3.5 cm. long, the empty beak long and slender. 



A weed in fields; native of Asia. 



228. SISYMBRIUM. 



Mostly annual or biennial herbs; leaves neither clasping nor 

 auriculate at the base, rarely entire, often finely dissected; 

 flowers small, usually yellow or yellowish; style short or none; 

 stigma 2-cleft; pod linear, short or long, flat or terete; seeds 

 oblong. 



Flowers white; leaves subentire, mostly basal. 5. thalianum. 

 Flowers yellow; leaves pinnate or pinnatifid. 



Stigma simple; pubescence of branched hairs. S. hartwegianum. 

 Stigma 2-lobed; pubescence of simple hairs. 



Pods short, subulate. 5. officinale. 



Pods long, linear. 5. altissimum. 



Sisymbrium thalianum (L.) Gay. Mouse-ear Cress. Slender annual, 

 10-20 cm. high, pubescent below; leaves mostly in a basal rosette, obovate to 

 oblanceolate, obtuse, entire or sparingly toothed, 2-5 cm. long; flowers usually 

 white; pods terete, somewhat 4-sided, usually purplish, about 1 cm. long, 

 scarcely longer than the slender pedicels. 



In dry ground, introduced from Europe. 



Sisymbrium hartwegianum Fourn. Loosely branched, 20-40 cm. high; 

 leaves pinnate with narrow lanceolate to oblong leaflets, these obtuse and 

 more or less toothed; pods crowded, erect, 5-7 mm. long, on suberect pedicels 

 nearly as long. 



Rare west of the Cascade Mountains; Charleston, Kitsap County, Washing- 

 ton, Piper. 



Sisymbrium officinale L. Hedge Mustard. Erect, sparsely hirsute with 

 simple hairs or glabrous, 30-90 cm. high, divaricately branched above; leaves 

 pinnatifid into 5-13 lobes, the terminal longest, all more or less dentate; upper 



