98 CRUCIFERA.E 



2. S. altissimum L. Tall Mustard. 2°-4° high : leaves deeply 

 pinnatifid : flowers j'ellowish-cream color : pods 2^-4' long, narrowly 

 linear. — Sparingly adventized along railroads at SheflSeld. May-Augnst. 



4. SINAPIS L. 



Flowers yellowish, racemose. Pods terete, beaked, constricted between 

 the seeds. Seeds roundish, not winged. Cotyledons conduplicate. 



1. S. alba L. White Mustard. 1°-3° high : leaves pinnate, with 

 a large terminal leaflet : pods ascending : beak as long or longer than the 

 pod. — Cultivated grounds and along railroads at Kansas City and Inde- 

 pendence. Rare. May-June. 



5. BRASSICA L. 

 Flowers yellow. Pods terete or four-sided, beaked, the beak usually 

 1-seeded. Seeds oblong, marginless. Cotyledons conduplicate. 



Leaves not clasping. 



Beak of fruit V'-2'' long. 1. B. nigra. 



Beak of fruit 5^^-6^^ long. 2. B. arvensis. 

 Upper leaves clasping. 



Leaves somewhat pubescent. 3. B. campestris. 



Leaves glabrous. 4. B. Najnts. 



1. B. nigra (L.) Koch. Black Mustard. 2°-6° high : leaves deeply 

 pinnatifid, dentate : pods narrowly linear, 6'^ long, smooth, on pedicels 

 2^^-4'^ long, appressed in fruit. — Abundant in waste places. June- 

 September. 



2. B. arvensis (L.) B.S.P. Charlock. 2°-3° high, hispid : leaves 

 pinnatifid : pods linear, knotty, 6''^-8'^ long, smooth, on short ascend- 

 ing pedicels. -Frequent along railroads, especially at Sheffield. May- 

 September. 



3. B. campestris L. Turnip. 1°-3° high, glabrous : lower leaves 

 pubescent, pinnatifid : upper leaves glabrous, auriculate, clasping and 

 entire : pods 1^-2'' long, on long spreading pedicels, long-beaked. — Infre- 

 quent in Avaste places and along railroads. May-September. 



4. B. Napus L. Rape. Like the last, but leaves entirely glabrous. — 

 Infreqi:eut along railroads. April-September. 



6. BARBAREA R. Br. 



Flowers yellow. Pod long-linear, four-sided. Seeds in one rojr in 

 each cell. Cotyledons accumbent. 



1. B . stricta Andrz. Winter Cress. 1°-2° high : le;wes lyrate- 

 pinnatifid : pods about V long, appressed on erect pedicels. — Along rail- 

 roads near the foot of Burge Park Bluffs, Kansas City. Rare. May. 



7. lODANTHUS T. & G. 

 Petals long-clawed, purplisli. Pods long-linear, cylindric. Seeds in 

 one row in each cell. Cotyledons accumbent. 



