CEUCIFER^E. (MUSTARD FAMILY.) 23 



1O. BARB ARE A, R. Br. WINTKR CRESS. 



Valves somewhat carinate. Seeds in one row, turgid, margiuless. Erect 

 and brandling, with angled stems. 



1. B. VUlgaris, R. Br. Stem 1 to 3 feet high: lower leaves lyrate* 

 pinnatifid, with a larger rounded terminal lobe and 1 to 5 pairs of lateral 

 ones ; upper leaves obovate, more or less piuuatifid at base : pods erect, often 

 appressed. From Oregon eastward. 



11. SISYMBRIUM, 1 L. HEDGE MUSTARD. 



Sepals scarcely gibbous at base. Seeds not margined. Erect herbs, with 

 small flowers, the leaves not clasping or auriculate, rarely entire. 



* Leaves pinnate or bipinnate. 



1. S. canescens, Nutt. Canescent with short branching hairs: stems 

 to 2 feet high : leaves 1 to 2-piimate, with the segments more or less deeply 

 pinnatifid or toothed : pods acute at each end and pointed with the very short 

 style, shorter than the slender spreading pedicels : seeds in two rows. Very 

 common on the plains and in the mountains. From Colorado to Arctic 

 America, westward to California, and eastward to New York and Pennsyl- 

 vania. 



2. S. incisum, Engelm. Pubescence short, more or less glandular : stems 

 1 to 4 feet high : leaves pinnate, with the segments linear to ovate-oblong, 

 more or less deeply piunatifid, sometimes entire : pods pointed at both ends, 

 mostly exceeding the spreading pedicels : seeds in one row. S. Calif or nicum, 

 Watson in Bot. King's Exp. 23. Oregon and Washington Territory, east- 

 ward to Winnipeg Valley and southward to New Mexico. 



* * Leaves entire or toothed. 



3. S. glaucum, Nutt. Glaucous, about 1 foot high: radical leaves 

 small, spatulate ; cauline ovate, sagittate and clasping, rather acute : floicers 

 very small, pale purple : pods erect : seeds in one or two rows. South Park, 

 Colorado, and northwestward to Oregon. 



4. S. virgatum, Nutt. Canescently hirsute with simple and stellate hairs: 

 stem about a span high, virgately branched from the base : leaves lanceolate- 

 linear, clasping ; lower ones denticulate or entire : flowers larger, pale purple : 

 pods erect : seeds in two rows. On the Platte and its tributaries. 



5. S. linifolium, Nutt. Glabrous and glaucous, 1 to l feet high : leaves 

 .narrowly oblanccolate or linear: flowers light yellow: pods ascending on short 



spreading pedicels, with short thick styles : seeds in one row. S. junceum of 

 Hayd. Rep. 1871, 1872. W. Wyoming and northwestward through Montana 

 and Idaho. 



1 BRASSICA is an allied genus, represented in our range by the following introduced 

 species : 



B. Sinapistrum, Boiss. Known by its rough spreading hairs, lower leaves usually with a 

 large coarsely toothed terminal lobe, upper leaves often undivided, and the pods more than 

 a third occupied by the stout 2-edgcd beak. Around settlements in S. Montana and Idaho, 

 ;uid undoubtedly elsewhere. 



