138 CRUCIFERJii. Sisi/inbrium. 



S. axirioiolatlim, Gray. Erect, 1 to 3 feet high, branched, somewhat hirsute or hispid 

 below with scattered hairs : leaves 3 to 6 inches long; segments triangular or oblong, 

 toothed or more frequently entire; the upper segments opposite; the lower reduced and 

 scattered upon the slender petioles : racemes becoming elongated ; fruiting pedicels divari- 

 cate, 3 to 5 lines. long: flowers small, white or nearly so: siliijues 15 to 20 lines long, slender, 

 widely spreading, often curved. — PI. Wright, i. 8, & ii. 12; Fourn. Sisymb. 102. Theh/po- 

 dium uuriculatum, Wats. Proc. Am. Acad. xvii. 321 ; Coulter, Contrib. U. S. Nat. Herb. ii. 

 15. — Moimtain valleys of W. Texas, Wright, Havard ; fl. March to July. (Mex., Gregg, 

 Palmer, Pringle.) The 2-lobed stigma with lobes lying over- the placeutai argues for the 

 present restoration of this species to Sisymbrium. 



* * Leaves (at least the cauline) entire, sessile by a sagittate-clasping base. 



S. (?) Vaseyi, Watson, in herb. Tall, erect, glabrous, probably glaucous, branching above : 

 leaves oblong, acutish, 2 to 4 inches long, lialf inch broad : flowers small, white or nearly so, 

 in numerous short racemes together forming an open corymbose panicle : pedicels short, 

 spreading: pods terete, erect, 8 to 12 lines long. — Thelyjmdium I a.scyj, Coulter, Contrib. 

 U. S. Nat. Herb. i. 30, & ii. 15, t. 1, as to plant of Vasey. (The plate is confused, the fruit- 

 ing branch being evidently of Neally's plant and distinct.) — Mountains west of Las Vegas, 

 New Mexico, G. Ii. Vasey, 1881, nos. 29, 4L A little known plant of thelypodioid habit but 

 with the short round buds, short anthers, and placeutai stigma-lobes of Sisymbrium. 



* * * Leaves entire or with one or two teeth or lobes (very rarely pinnatifid), subsessile 

 by a cuneate base. ^ 



S. linifolium, Nutt; Perennial, slightly woody at the base, quite glabrous : stems several, 

 .slender, terete, erect, flexuous : leaves narrowly oblanceolate or oblong to linear, thicki.sli, 

 1 to 3 inches long : flowers 4 lines long, yellow : pods slender, spreading, curved upwards, 

 1 to \l inches long, half line in thickness; pedicels 3 lines in length. — Nutt. in Torr. & 

 Gray, Fl. i. 91, 667. S. junceum. Hook. Fl. Bor.-Am. i. 61 ; Torr. & Gray, Fl. i. 91 ; not 

 Biebers. Nasturtium linifolium & }>umilum, Nutt. Journ. Acad. Philad. vii. 12. Erysimum 

 ('i)glaberrimum. Hook. & Arn. Bot. Beech. 323. — Colorado, Jones, and Wyoming, Parry, to 

 S. Brit. America, Macoun ; Washington, Suksdorf; Oregon, Howell Bros., to N. Arizona, 

 Palmer; fl. May to August. 



§ 3. Descurea, C. a. Meyer (extended). Pubescence branched, rarely 

 glandular, very rarely none: stigma small, entire. — Mey. in Ledeb. Fl. Alt. iii. 

 13;3. Descurainia, Webb «& Berth. Phyt. Can. i. 72 (as to § Sophia). 



* Cauline leaves entire or nearly so, sessile, sagittate-amplexicaul. 

 S. virgatum, Nutt. A cinereous-tomentose biennial, 6 to 15 inches high, often branched 

 from the base : radical leaves numerous, rosulate, oblong, toothed, obtuse, petiolate : fruiting 

 pedicels spreading, 3 to 5 lines long: siliques 8 to 14 lines in length, erect, — Nutt. in Torr. 

 & Gray, Fl. i. 93 ; Fourn. 1. c. 105; Gray, Proc. Acad. Philad. 1863, 57; Coulter, Man. 

 Rocky Mt.Reg. 23. — Rocky Mountains of Colorado and W^yoming, northward to Brit. 

 America, from Wood Mt. to Medicine Hat, Macoun. The northern specimens are more 

 paniculately branched ; fl. early summer. 



S. I'ATciFLORUM, Nutt. 1. c, of the same region, described as a biennial with branched pubes- 

 cence, white flowers, and long pendulous siliques, has always been obscure, and appears to have 

 been founded upon immature specimens of Arabis canesrens. 



* * Cauline leaves more or less undulate-dentate or pinnatifid with broad rounded seg- 

 ments, not clasping : capsules attenuate, pubescent. 



S. diffusum, Gray. Tall and slender, diffusely branched, cinereous-tomentose : stem 

 terete, leafy, often flexuous above : petioles short ; the upper leaves subsessile : petals white, 

 2^ lines in length ; fruiting pedicels nearly horizontal : pods widely spreading, almost divari- 

 cate, rarely suberect; midrib of the septum very broad. — PI. Wright, i. 8; Torr. Bot. Mex. 

 Bound. 33; Coulter, Contrib. U. S. Nat. Herb. i. 30, & ii. 16. — Mountains and rocky hUls of 

 W. Texas, //am;c/; New Mexico, Wright; S. Arizona, Lemmon ; Coso Mountains, Calif., 

 Coville & Fnnston. (Chihuahua, Pringle.) 



* * * Leaves pinnately parted with narrow segments, or hi- to tri-pinnatifid (witii seg- 

 ments narrow or broad) : capsules glabrous, obtuse or merely acutish. 



•i- Seeds biseriate in each cell. 



