II.] 



MUSTARD FAMILY. 



129 



4. Cardamine arenicola Britton. 

 Sand Bitter-cress. (Fig. 1727.) 



Cardamine Virginica Michx. Fl. Bor. Am. 2: 29. 

 1803. Not Iv. 1753. 



Cardamine arenicola Britton, Bull. Torr. Club, 19: 

 220. 1892. 



Glabrous, usually much branched from the 

 base, leafy nearly or quite up to the racemes, 

 -erect, 6 / -i2 / high. Segments of the leaves 

 numerous, linear or linear-oblong, X // ~ I /^ // 

 wide, obtusish, entire, or with 1-3 small teeth, 

 those of the basal ones slightly wider than 

 those of the upper; flowers about 2 r/ broad, 

 white; mature pods strictly erect, less than i' 

 long, X // ~^ // wide, their pedicels ascending; 

 style almost wanting. 



In moist or wet sandy soil, Connecticut to Flor- 

 ida, Kentucky and Tennessee. March-April. 



5. Cardamine parviflora L,. Small- 

 flowered Bitter-cress. ( Fig. 1728.) 



Cardamine parviflora L. Sp. PI. Ed. 2, 914. 1763. 

 Cardamine hirsuta var. sylvatica A. Gray, Man. 

 Ed. 5, 67. 1867. 



Glabrous or very sparingly pubescent, stem 

 weak, erect or ascending, very slender or almost 

 filiform, 2 / -i5 / long, usually leafy up to the ra- 

 cemes, but the leaves scattered. Segments of 

 the leaves numerous, oblong or linear, or the 

 terminal ones sometimes orbicular, entire or 

 sparingly toothed, % /f -2 ff wide; mature pods i' 

 long or less, rather less than %" wide, erect on 

 ascending pedicels, 2 // ~5 // long, the axis of the 

 racemes commonly zigzag; flowers scarcely more 

 than i" broad, white; style almost wanting. 



On dry rocks. Quebec to western Ontario and 

 Oregon, south in the Alleghanies to Georgia. Also 

 in northern Europe and Asia. April-May. 



6. Cardamine flexuosa With. Wood 

 Bitter-cress. (Fig. 1729.) 



Cardamine flexuosa With. Bot. Arr. Brit. PI. Ed. 

 3, 3: 578. 1796- 



Glabrous, rather dark green, stem slender or 

 rather stout, branched, leafy, 6 / -i5 / tall. Leaf- 

 segments obovate, oval, oblong or linear, the 

 terminal one sometimes orbicular, narrowed 

 rounded or subcordate at the base, 5 // -io // wide, 

 the lateral ones usually much narrower; flowers 

 white, 2 r/ broad; pods ascending or divergent, on 

 spreading or ascending pedicels, 8 // -i5 // long, 

 Yz" wide or rather more; style W long or less. 



In wet woods, streams and mountain swamps, 

 Maine to Michigan, south to North Carolina, espe- 

 cially in the mountains. Also in Europe and Asia, 

 and apparently in Washington. May-Aug. 



