138 "CRUCIFERiE. Sist/mbrium. 



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

 below with scattered liairs : leaves 3 to 6 iuches 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: siliques 15 to 20 lines long, slender, 

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

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

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

 Palmer, Pringle.) 'J'he 2-lobed stigma with lobes lying over the placentae 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, half inch broad : flowers small, white or nearly so, 

 in numerous short racemes together forming an open corymbose ]janicle : jjedicels short, 

 spreading: pods terete, erect, 8 to 12 lines long. — Thelypodium 1 use j/?, 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. R. Vasey, 1881, uos. 29, 41. A little known plant of thelypodioid habit but 

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



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

 by a cuueate 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, thickish, 

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

 1 to 1^ 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 & pumilum, Nutt. Journ. Acad. Philad. vii. 12. Erysimum 

 {I) glaberrimiim, Hook. & Arn. Bot. Beech. 323. — Colorado, Jones, and Wyoming, Parry, to 

 S. Brit. America,^ J/aco!«j ; 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. 

 135. Descurainia, Webb & Berth. Phyt. Can. i. 72 (as to § Sopliia). 



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

 S. virgatum, Nutt. a cinereou.s-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 Wyoming, northward to Brit. 



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



paniculately branched ; fl. early summer. 



S. PAiTCiFLORUM, 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 canescens. 



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

 ments, not clasping : capsules attenuate, pubescent. 



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

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

 2h 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 hills of 

 W. Texas, Havard ; New Mexico, Wright; S. Arizona, Zem?7io« ; Coso Mountains, Calif., 

 Coville & Funston. (Chihuahua, Pringle.) 



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

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



-1— Seeds biseriate in each cell. 



