GENUS 12. 



MUSTARD FAMILY. 



4. Radicula sphaerocarpa (A. Gray) 

 Greene. Round-fruited Cress. 

 Fig. 2029. 



Nasturtium sphaerocarpum A. Gray, Mem. Am. Acad. 



4 : 6. 1849. 

 Roripa sphaerocarpa Britton, Mem. Torr. Club 5 : 



170. 1894. 

 ^?. obtusa sphaerocarpa Robinson, Rhodora 10 : 32. 



1 908. 

 Radicula sphaerocarpa Greene, Leaflets, i : 113. 1905. 



Glabrous, stem erect or decumbent, usually 

 branched, slender, 4'-! 2' high. Leaves oblong, 

 obtuse, the lower lyrate-pinnatifid or incised, the 

 upper sometimes nearly entire, all petioled or the 

 upper subsessile; petioles narrowly margined, 

 somewhat clasping at the base ; flowers i" broad 

 or less; petals yellow, about equalling the sepals; 

 silicic globose, or subglobose, i"-2" in diameter, 

 about as long as its pedicel ; style very short. 



Illinois to Kansas, Texas and California. Perhaps 

 a short-podded race of the preceding species. June- 

 July. 



5. Radicula palustris (L.) Moench. Marsh or Yellow Water-cress. Fig. 2030. 



Sisymbrium amphibium var. palustre L. Sp. 



PI. 657. I7S3- 



Radicula palustris Moench. Meth. 263. 1794. 

 Nasturtium terrestre R. Br. in Ait. Hort. Kew. 



Ed. 2, 4: no. 1812. 



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

 Roripa palustris Bess. Enum. 27. 1821. 



Annual, or biennial, erect, branching, 

 glabrous or slightly pubescent, i-3i high. 

 Lower leaves petioled, 3'-7' long, oblong 

 or oblanceolate, deeply pinnatifid (rarely 

 only dentate), the lobes acutish or blunt, 

 repand or toothed ; upper leaves nearly ses- 

 sile, dentate or somewhat lobed; base of 

 the petiole often dilated and clasping; pedi- 

 cels slender, 3" long in fruit; flowers yel- 

 low, 2"-3" broad; pods linear, or linear- 

 oblong, 2-6 times as long as thick, about 

 equalling the pedicels, spreading or curved ; 

 style i" long or less. 



In wet places, nearly throughout North 

 America except the extreme north. Appar- 

 ently in part naturalized from Europe on the 

 eastern side of the continent, but widely 

 indigenous. Yellow wood-cress. May-Aug. 



6. Radicula hispida (Desv.) Britton. 

 Yellow-cress. Fig. 2031. 



Hispid 



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

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

 Nasturtium palustre var. hispidum A. Gray, Man. Ed. 2, 



30. 1856. 



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

 Radicula hispida Britton, Torreya 6: 30. 1906. 

 R. palustris hispida Robinson, Rhodora 10: 32." 1908. 



Resembling the preceding species, but often stouter, 

 sometimes 4 high and with lower leaves 10' long, 

 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 Alaska, British Co- 

 lumbia. Florida and New Mexico. Europe. Summer. 



