CRUCIFER^. (mustard FAMILY.) 23 



10. BARBAREA, K.Br. Wimkk Cress. 



Valves somewhat carinate. Seeils iu one row, turgid, n>ar^'iiile.'<.s. — Erect 

 and branching, with angled .-^tenis. 



1. B. vulgaris, K. Br. stem 1 to 3 feet high: lower leaves lyrate- 

 ])innatitid, with a larger rounded ternjinal lobe and 1 to 5 pairs of lateral 

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

 appressed. — From Oregon eastward. 



11. SISYMBRIUM,! L. Hedge Mustard. 



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

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



* Leaves pinnate or bipinnate. 



1. S. canescens, Nutt. Canescent icith sliort brnnrhing hairs: stems 

 ^ to 2} feet higli : leaves 1 to 2-pinnate, with the segments more or k'.«;s deojily 

 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. — Verv 

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

 America, westward to California, and eastward to New York and Penn.'syl- 

 vania. 



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

 1 to 4 feet high : leaves pinnate, with the segments linear to ovate-ol)long, 

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

 mostly exceeding the spreading pedicels: seeds in one row. — S. Calijornicitm, 

 Watson in Bot. King's Exp. 23. Oregon and AVashington, eastward to Win- 

 nipeg Valley and southward to New Mexico. 



* * Leaves entire or toothed. 



3. S. glaucum, Nutt. Glaucous, about 1 foot high: radic;il leaves 

 small, spatithtfe ; cauline ovate, sagittate and clasping, rather acute : flmrers 

 verg small, pale purple: pods erect : seeds in one or two rows. — South Bark 

 Colorado, and northwestward to Oregon. 



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

 stem about a span high, virgatelg branched from the l)asc : 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 U foot high: leaves 

 narrowlij ohhniccolate or linear : flowers light yellow: pods a.<«cendiiig on short 

 spreading pedicels, with short thick styles: seeds in one row. — .*^. iunmni} of 

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

 and Idaho. 



» Brassica is an allied penus, represented in our mnjze l>y the following introduoed 

 species : — 



B. Sinapi.<<trum, Boiss. Known by its roupli spreading Imirs. lower l«'.Tves nsn.nlly witli .i 

 large coarsely tootlied terminal lohe, nj>per leaves often luvlivided, and tlio pods more tli.in 

 n third occupied by the stout 2H-<lgcd beali. — Around settlements in S. .Montana and Idaho, 

 and undoubtedly elsewhere. 



