CRUCIFER^E. (MUSTARD FAMILY.) 23 



10. B ABB ARE A, R. Br. WINTER CRESS. 



Valves somewhat earinate. Seeds iu one row, turgid, margiuless. Erect 

 and brandling, with angled stems. 



1. B. vulgaris, R. Br. Stem 1 to 3 feet high: lower leaves lyrate- 

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

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

 appressed. From Oregon eastward. 



11. SISYMBBIUM, 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 : steins 

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

 more or less deeply pinnatifid, 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 : .floiccrs 

 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 oblanceolate or linear : flowers light yellow : pods ascending on short 

 spreading pedicels, with short thick styles : seeds in one row. S.juncenm 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 nstially with a 

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

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

 and uudoubtedly elsewhere. 



