VOL. II.] 



MUSTARD FAMILY. 



125 



4. Roripa sphaerocarpa (A. Gray) 



Britton. Round-fruited Cress. 



(Fig. 1716.) 



Nastztrtium sphaerocarpum A. Gray, Mem. Am. 

 Acad. 4: 6. 1849. 



Roripa sphaerocarpa Britton, Mem. Torr. Club, 5: 

 170. 1894. 



Glabrous, stem erect or decumbent, usually 

 branched, slender, 4 / -i2 / high. Leaves oblong, 

 obtuse, the lower lyrate-pinnatifid or incised, 

 the upper sometimes nearly entire, all petioled 

 or the upper subsessile; petioles narrowly mar- 

 gined, somewhat clasping at the base; flowers i" 

 broad or less; petals yellow, about equalling the 

 sepals; silicle globose, about \" in diameter, 

 about as long as its pedicel; style very short. 



Illinois to Kansas, Texas and California. June- 

 July. 



5. Roripa palustris (I,.) Bess. Marsh 



i 



or Yellow Water-cress. ( Fig. 1717.) 



Sisymbrutni amphibium var. palustre L. Sp. 



PI- 657- 1753- 

 Nasturtium terrestre R. Br. in Ait. Hort. 



Kew. Ed. 2, 4: no. 1812. 

 Nasturtium palustre DC. Syst. 2: 191. 1821. 

 Roripa palustris Bess. Enum. 27. 1821. 



Annual, or biennial, erect, branching, 

 glabrous or slightly pubescent, i-3^ 

 high. Lower leaves petioled, $'-"1' long, 

 oblong or oblanceolate, deeply pinnatifid 

 (rarely only dentate), the lobes acutish 

 or blunt, repand or toothed; upper leaves 

 nearly sessile, dentate or somewhat lobed; 

 base of the petiole often dilated and clasp- 

 ing; pedicels slender, 3 // long in fruit; 

 flowers yellow, a // -3 // broad; pods linear, 

 or linear-oblong, 2-6 times as long as 

 thick, about equalling the pedicels, spread- 

 ing or curved; style W long or less. 



In wet places, nearly throughout North 

 America except the extreme north. Appar- 

 ently naturalized from Europe on the eastern 

 side of the continent, but evidently indige- 

 nous in the west. May-Aug. 



6. Roripa hispida (Desv.) Britton. His- 

 pid Yellow-cress. (Fig. -1718.) 



Rrachylobus hispidus Desv. Journ. Bot. 3: 183. 1814. 

 Nasturtium hispidum DC. Syst. 2: 201. 1821. 

 Nasturtium palusfrevax. hispidum A. Gray, Man. Ed. 



2, 30. 1856. 



Roripa hispida Britton, Mem. Torr. Club, 5: 169. 1894. 

 Roripa palustris hispida Rydberg, Contr. U. S. Nat. 



Herb. 3: 149. 1895. 



Resembling the preceding species, but often 

 stouter, sometimes 4 high, the stem, branches, 

 petioles and veins of the lower surfaces of the 

 leaves hirsute with spreading hairs. Leaves lyrate- 

 pinnatifid; pedicels slender, spreading, about 3" 

 long, longer than the globose or ovoid pod, which 

 is 1-2 times as long as thick. 



In wet places. New Brunswick to British Columbia. 

 Florida and New Mexico. Lower leaves sometimes 

 10' long. Summer. 



