CRUCIFER^E. 33 



1. 8. officinale De Cand. : leaves runcinate and with the stem hairy ; 

 flowers in a long raceme ; pod subulate, pressed to the rachis. Ery- 

 simum officinale Linn. 



HAB. Road sides. Throughout the U. S. and Can. W. to Colum- 

 bia river. June Sept. 0. Stem 1 2 feet high, branched. 

 Leaves hairy, or nearly smooth. Flowers yellow, minute. Va- 

 ries much in the character of its leaves. Hedge Mustard. 



2. <S>. sophia Linn. : leaves bipinnate, smooth or pubescent; segments 

 oblong-linear, cut ; petals shorter than the calyx ; calyx thrice as short 

 as the pedicel ; pod linear, erect. 



HAB. Sandy places. Can. June, July. . Stem 8 12 in- 

 ches high. Flowers yellow, numerous. Fruit-bearing-raceme 

 very long. I have received a specimen of what I think must be 

 the true S. sophia from Dr. Holmes of Montreal. The pods are 

 very narrow-linear, 1-2 to 3-4 of an inch, longer and narrower 

 than in S. canescens of Nuttall, and not clavate as in the latter. In 

 other respects I cannot observe any difference between these 

 two plants. 



19. ERYSIMUM. Linn. 



Pod four-sided. Calyx closed. Cotyledons flat, oblong. 



Tetr adynamia. Siliqnosa. 



1. E. cheirantftoides Linn. : leaves lanceolate, somewhat toothed and 

 scabrous ; pod erect-spreading, twice as long as the pedicel ; stigma 

 small, nearly sessile. 



HAB. Fields. Near Fairfield, N. Y. Can. and on all the plains west- 

 ward of the Rocky mountains. July. %j, Stem 1 2 feet high, 

 erect, and with the leaves scabrous. Flowers yellow, in longter- 

 minal racemes. Pods linear, somewhat spreading, 1-2 to 3-4 of 

 an inch long. 



20. SINAPIS. Linn. 



Pod roundish ; valves bearing nerves ; style small, short, 

 acute. Seeds in one series, subglobose. Calyx spreading. 



Tetr adynamia. Siliquosa. 



1. S. nigra Linn. .- lower leaves lyrate ; upper ones lanceolate, en- 

 tire, petiolate ; pod smooth and even, somewhat 4-sided, appressed to 

 the peduncle. 



HAB. Fields. N. S. June, July. Q.Stem 24 feet high. 

 Flowers yellow. Common Mustard. 



2. S. alba Linn. : leaves lyrate, nearly smooth, the terminal lobe 

 large ; pod mostly hispid, spreading, shorter than the broad sword- 

 form beak ; seeds large, pale. 



HAB. Waste places. N. S. July. 0. Steml 2 feet high. Pinc- 

 ers yellow, rather large, corymbose. Introduced. White Mustard. 



