This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Sisymbrium Sophia L. Sp. Pl. 659. 1753.
Descurainia Sophia Webb; Prantl in Engler & Prantl, Nat. Pflf. 32: 192. 1892.
Sophia Sophia Britton, in Britt. & Brown, 1ll. Fl. 2: 144. 1897.
Minutely hoary-canescent, stem usually much branched, 1°-2 1/2° tall, quite bushy. Leaves 2-3-pinnatifid into narrowly linear or linear-oblong segments; flowers very numerous, about 3" long; pedicels ascending, very slender, 6"-8" long, glabrous or nearly so; pods narrowly linear, 8"-12"long, 1/2" thick, ascending, curved upwards; seeds in 1 row in each cell of the pod.
In waste places, New Brunswick to Ontario, Washington, Oregon, New York, Illinois, Nebraska and Utah. Naturalized from Europe. Native also of Asia. June-Aug. Fine-leaved hedge-mustard. Flaxweed.
Erysimum pinnatum Walt. Fl. Car. 174. 1788. Sisymbrium canescens Nutt. Gen. 2: 68. 1818. Descurainia pinnata Britton, Mem. Torr. Club 5: 173. 1894. S. pinnata Howell, Fl. N. W. Am. 1: 56. 1897. Sophia brachycarpa (Richards.) Rydb.; Britton, Man. 462. 1901.
Densely canescent nearly all over, to glabrate; stem erect, branched, 8'-24' tall, slender, the branches ascending. Leaves 2'-4' long, oblong in outline, 2-pinnatifid into very numerous small toothed or entire obtuse segments; pedicels very slender, spreading nearly or quite at right angles to the axis, 5"-7" long, usually longer than the pods; flowers 1"-1 1/2" broad; pods horizontal or ascending, oblong or linear-oblong, compressed, 3"-4" long, 1" wide, glabrous or somewhat canescent; style minute; seeds plainly in 2 rows in each cell.
Resembles the preceding species, but is greener, nearly glabrous, or the pubescence is mixed with short glandular hairs. Leaves pinnately divided, and the pinnae 1-2-pinnatifid into linear-oblong entire or toothed segments; fruiting pedicels widely ascending, filiform, 5"-10" long, usually longer than the pods; pods 4"-7" long, about 1" thick, somewhat swollen, erect or ascending; seeds in 1 row or indistinctly in 2 rows.
In dry soil, Minnesota to Saskatchewan and British Columbia, south to Tennessee, Kansas, Texas and California. May-Aug.
Sisymbrium Hartwegianum Fourn. Sisymb. 66. 1865. Sisymbrium incisum var. Hartivegianum Brew. &
Similar to the two preceding species, densely minutely canescent or puberulent, stem 1°-2° tall, the branches slender, ascending. Leaves usually less finely dissected, pinnately divided into 5-7 pinnae, which are pinnatifid with obtuse segments and lobes; fruiting pedicels erect-appressed or closely ascending, 1 1/2"-4" long, shorter than or equalling the pods; pods erect or nearly so, linear, 4"-5" long, about 1/2" thick; seeds in 1 row.
In dry soil, Minnesota to Saskatchewan, British Columbia, Colorado, Utah, Mexico and California. May-July.