336 BRASSICACEAE 



yellow, about, 2.5 mm. long, spatulate; pedicels in fruit spreading; pod 7-10 

 mm. long, 2 mm. thick; st^de 0.5-0.75 mm. long. Roripa pacifica Howell. Wet 

 places: Alaska — Wash. — Utah — Alta. Suhmont. My-Au. 



7. R. hispida (DC.) Heller. Biennial; stem stout, branched above, 3-12 dm. 

 high; leaves lyrate-pinnatifid, with lanceolate or ovate, toothed divisions; petals 

 spatulate, yellow, 2 mm. long; fruiting pedicels ascending or spreading; pod 4-6 

 mm. long, 2 mm. thick, glabrous; style about 1 mm. long, N. hispidum DC. 

 Water and wet places: N.B.— Fla. — N.M. — Wash. — Utah— Alaska. Plain— 

 Subinont. Je-Au. 



8. R. terrestris (R. Br.) Woot. & Standi. Annual or biennial; stem branched 

 above, 3-10 dm. high; leaves lyrate-pinnatifid, with oblong or lanceolate, toothed 

 divisions; petals yellow, spatulate, 2 mm. long; fruiting pedicels usually spreading; 

 pod 5-7 mm. long, 2 mm. thick; style 1 mm. long. Sisymbrium amphihium 

 palustre L. N. terreslre R. Br. N* palustre DC. Radicula palustris (L.) Moench. 

 Water and wet places: Lab. — Ga. — N.M. — Alaska; Eurasia, Mex. Plain— 

 Submont, Ap-0. 



9. R. alpina (S. Wats.) Greene. Biennial; stem branched below, 1-3 dm. 

 high; leaves sinuately lobed, rarely pinnatifid, elliptic or oblanceolate, obtuse; 

 petals spatulate, 2.5 mm, long; pedicels spreading; pod about 5 mm. long, 2 mm. 

 thick; beak about 0.5 mm. long. A^. obtusum cdpinum S. Wats. Wet places m 

 the mountains : Mont. — Colo. — Utah — Ida. SubmonL — Subalp, Jl-Au. 



10. R. sphaerocarpa (A. Gray) Greene. Annual or biennial; stem diffusely 

 branched from the base, 1-3 dm. high, glabrous; leaves sinuately or lyrately 

 lobed, with rounded lobes; petals yellow, 1.5 mm. long; pedicels 2-3, rarely 5 mm. 

 long; pod 2-3 mm. long, nearly 2 mm. thick; style about 0.5 mm. long. N- 

 sphaerocarpum A. Gray. Along streams: IlL—Tex. — -Calif. — Wyo. Plain 

 Submont. Jl-S. 



11. R. obtusa (Nutt.) Greene. Annual; stem diffusely branched at the 

 base, 1-3 dm. high, glabrous; leaves pinnatifid, with obovate or rounded, smu- 

 ately toothed divisions; petals narrowly spatulate, 1 mm. long; pedicels ascend- 

 ing or spreading; pod 4-8 mm. long, 1-2 mm. thick; style about 1 mm. long. 

 A^. obtusum Nutt. Wet places: Mich.— Mo.— Tex.— Utah— Wash. Plain— 

 Submont. Je-S. 



12. R. curvipes Greene. Annual; stems 1-3 dm. high, diffusely branched; 

 leaves lyrate-pinnatifid or lobed, usually with acute divisions; petals about 1 

 mm. long; pedicels spreading or recurved; pod about 5 mm. long, somewhat 

 curved, about 2 mm. thick, acute at the apex. Roripa curvipes Greene. Wet 

 places in the mountains: Utah — -Wyo, — N.M. Submont. — Subalp. Jl-S. 



13. R. curvisiliqua (Hook.) Greene. Annual or biennial; stem diffusely 

 branched, 1-3 dm. high, glabrous; leaves pinnately divided, with many oblong, 

 mostly obtuse divisions, glabrous; petals yellow, 2.5 mm. long, oblanceolate; 

 pedicels 4-5 mm. long; pod curved, 8-12 mm. long, about 1 mm. thick. ^^^^^[' 

 brium curvisiliquum Hook. N. curvisiliquum Nutt., in part. Wet places: Mont. 

 —Wyo.— Ore.— Wash. ^ily-S. 



14. R. Nuttallii (S. Wats.) Greene. Biennial; stems solitary or several, 

 erect, rather simple, 3-4 dm. high, glabrous; leaves pinnately lobed or tootnea, 

 with lanceolate or triangular lobes or teeth, or the lower ones with linear divis- 

 ions; petals 2-2.5 mm. long, oblanceolate; pedicels 2-4 mm. long; pod 8-15 mm. 

 long, 1 mm. thick, somewhat curved. AT. curvisiliqua Nuttallii S. ^\ ats. ^^ 

 Nuttallii Rydb. Wet places: Wash -—Calif.— (? Mont.) 



15- R. lyrata (Nutt.) Greene. Annual; stems diffusely branched, 1-3 dm. 



high, glabrous; leaves pinnately divided, with oblong to ovate, coarsely tootnea 

 divisions; petals scarcely 1 mm. long; pedicels 1-3 mm. long, ascending; poa 

 6^15 mm. long, 1-1.5 mm. thick. AT. lyratum Nutt. Wet places: Mont.— ooio. 

 — Calif. — Wash. Plain— Submont. Jl-Au. 



16. R. Underwoodii (Rydb.) Heller. Biennial; stem 2 dm. or more high, 

 divaricately branched, perfectly glabrous; leaves 3-5 cm. long, lyrately pinna- 

 tifid, thin; lobes oblong, obtuse, the terminal one elliptic to broadly oval, smu- 



