92 CRUCIFERyE. Sisymbrium. 



§ 3. Siliques terete : seeds ovate, someiohat triangular: flowers yellow. 

 — Irio, DC. 



5. S. Sophia (Linn.) : leaves bipinnatifidly divided ; lobes oblong-linear, 

 incised; pedicels 4 times the length of the calyx ; petals smaller than the 

 sepals. DC.—Fursh, ft. 2. p. 440?; DC.prodr. \.p. 193. 



Near Quebec, and "other parts of Lower Canada, Mrs. Percival ! near 

 Montreal, Dr. Holmes ; Virginia, Pursh. Apparently native in Canada. 

 July. — (^ Plant 2 feet high. Segments of the leaves less than a line in 

 breadth. Siliques an inch long, linear, very narrow. 



6. S. sophioides (Fischer) : leaves bipinnatifid; lobes ovate or lanceolate, 

 incised ; pedicels (and petals) somewhat shorter than the calyx ; siliques 

 linear-filiform, falcate, and, as well as the flowers, in umbeUiform corymbs. 

 Hook.—Fisch. in Hook. Jl. Bor.-Am. 1. p. 61. t. 20. S. Sophia, Cham, f 

 Schlecht. in Linnoia, 1. p. 28. S. Sophia, var. ? Richards, app. Frankl. 

 journ. p. 27. 



Hudson's Bay to Kotzebue's Sound.— @ Stem branching, flexuous, near- 

 ly glabrous. Peduncles glandular-pubescent. Flowers deep yellow. SiU- 

 ques densely umbelled (not elongated into a raceme in fruit), 2 inches long, 

 3 times the length of the pedicels. 



7. S. canescens (Nutt.) : leaves bipinnatifid ; lobes oblong or lanceolate, 

 somewhat toothed ; petals scarcely exceeding the calyx ; siliques in elongat- 

 ed racemes, oblong or oblong-linear, shorter (or rarely longer) than the 

 pedicels. 



a. canescent ; lobes of the leaves obtuse (or obovate) ; siliques somewhat 

 clavate, about half as long as the pedicels. — S. canescens, Nutt. .' gen. 2. p. 

 68; DC.prodr. 1. p. 194; Ell. sk. 2. p. 147; Hook. Jl. Bor.-Am. 1. p. 62. 

 Erysimum pinnaium, Walt. Car. p. 174. Cardamine? Menziesii, DC. 

 prodr. 1. p. 153. (fide Hook.) 



Li. leaves minutely pubescent, but not hoary ; peduncles and pedicels spar- 

 ingly furnished with stipitate glands intermixed with simple pubescence ; 

 siliques as in var. a. 



y. leaves glabrous ; lobes obtuse, mostly entire ; stem and pedicels minutely 

 glandular ; siliques as in var. a. & 0. 



S. lobes of the leaves somewhat acute, and, with the stem, furnished with 

 minute stipitate glands ; petals rather longer than the calyx ; siliques scarcely 

 attenuate at the base, somewhat longer than the pedicels. — S. brachycar- 

 ^Mm, Richards. ! app. Frankl. journ. ed. 2. p. 27; DC.prodr. \.p. 194; 

 Hook. ft. Bor.-Am. 1. p. 62. 



€. (Californicum) : somewhat canescent ; lobes of the leaves acutely 

 toothed ; petals obovate, one-half longer than the calyx. 



f. (brevipes, Nutt. mss.) : " siliques usually longer than the pedicels. " 



a. Arctic America to Florida ! Arkansas ! Rocky Mountains, plains of the 

 Oregon, and Upper California, Nuttall. 0. Georgia ! Arkansas ! Texas ! 

 y. Kentucky, Short ! <5. Arctic America and Canada, ex Hook. ; Lake Su- 

 perior, Dr. Houghton ! Dr. Pitcher ! £. California, Douglas ! ?. Rocky 

 Mountains, Nuttall— (Tj Plant 1-2 feet high. Flowers very small (in var. 

 e. twice as large as in the other varieties). Pedicels spreading, with the 

 siliques often erect. 



§ 4. Siliques linear, compressed, somewhat terete: stigma nearly sessile: 

 flowers white {or rose-color) : peduncles usually short. — Arabidopsis, 

 DC. 



8. S. humile (Ledeb.) : canescently pubescent, perennial ; stems diffuse ; 

 leaves entire or sinuate-toothed ; radical ones spatulate ; cauline ones lanceo- 



