June, 1917] The Brassicacece of Ohio 329 



1. Sinapis alba L. White Mustard. Stem branching, 

 hispid-pubescent, 1-2 ft. high; lower leaves with a large terminal 

 leaflet and several pairs of smaller ones, dentate, 6-8 in. long; 

 upper leaves smaller, to lanceolate, dentate; pods bristly, 

 constricted, ascending, beak as long as the pod. 



A European herb, escaped from cultivation. Lucas County. 



2. Sinapis arvensis L. Corn Mustard. Stem branching 

 1-2 ft. high; leaves like those of S. alba, but less lobed, the 

 upper leaves rhombic, sessile; pods glabrous, knotty, ascending, 

 beak ^ as long. 



A troublesome annual from Europe. General, except in 

 southern part. 



31. Brassica (Tourn.) L. Cabbage, Mustard, Turnip. 



Annual or biennial erect branching herbs, sometimes tall, 

 with pinnatifid or lyrate basal leaves, dentate or entire upper 

 leaves, and showy yellow flowers in long racemes. Siliques 

 long, sessile, terete or 4-sided, tipped with a conic, often 1-seeded 

 beak. Seeds globose, wingless, in 1 row in each cavity. 



1. Leaves not clasping at the base. 2. 



1. Upper leaves clasping at the base. 3. 



2. Plant green, hirsute; pods appressed. B. nigra. 



2. Plant pale glaucous, glabrous; pods spreading. B. jiincea. 



3. Leaves auricled. 4. 



3. Leaves not auricled; plant glaucous-blue. B. oleracea. 



4. Plant hispidulous. B. campestris. 

 4. Plant entirely glabrous. B. napiis. 



1. Brassica nigra (L.) Koch. Black Mustard. Stems 2-7 

 ft. high, branching, bristly, with scattered hairs; leaves hispid or 

 hirsute, lower leaves with one large terminal lobe and several 

 small lateral ones; upper leaves lanceolate, nearly entire; 

 flowers bright yellow; pods linear, 4-sided, appressed; seeds 

 dark brown, pungent. 



A common weed, introduced from Europe. 



2. Brassica juncea (L.) Cosson. Indian Mustard. Stems 

 1-4 ft. tall, coarse, pale, glabrous and somewhat glaucous; 

 lower leaves lyrate, 4-(5 in. long, petioled; upper leaves much 

 smaller, lanceolate or oblong, nearly entire, sessile; flowers 

 larger than those of B. nigra; pods long, spreading. 



In grain fields and waste places, recently introduced from 

 Asia. Portage, Wayne. 



