64 BOTANY. 



Sisymbrium canescens, Nutt. — Colorado and Nevada. From Ash 

 Creek, Arizona, I have specimens (306) that are an enigma to me ; the very- 

 sharp cut to the leaves, the great glandular-hairiness, the linear pods, 

 and filiform pedicels almost tempt me to call it a new species It does 

 not appear to be either incisum of Engelman or auriculatum or diffusum 

 of Gray. 



Sisymbrium incisum, Engelm. (PI. Fend. p. 8). (S. Californicum, Wat- 

 son, in King's Report ) — Nevada and Utah. 



Sisymbrium virgatum, Nutt. — " 6-12' high ; stems simple or branched 

 from the base (or sometimes branched above), slender, covered below with 

 an ashy, simple, or forked pubescence ; leaves tomentose pubescent ; those 

 of the root petioled, lanceolate-oblong, and sinuate-dentate ; stem leaves 

 sessile, lanceolate, auriculate, and clasping at base, entire, denticulate, or 

 slightly wavy-margined, 6-8" long ; flowers pale purple, 2" in diameter ; 

 stigma almost sessile; pods 1-1 £' long, and 3-4 times exceeding the slender 

 pedicels; seeds 4-angled, 'in a double series.'" (605, 606, 652.) South 

 Park and Twin Lakes, Colorado. 



Smelowskia calycina, Meyer. — Alpine regions of Colorado. (601.) 



Erysimum cheiranthoides, L. — Twin Lakes, Colorado, 9,000 feet 

 altitude. (651.) 



Erysimum asperum, DC. — Nevada and Utah. 



Erysimum asperum, DC, var. Arkansanum, Nutt. — Central Colorado. 

 (593, 596, 599, 640.) 



Erysimum asperum, DC, var. pumilum, Watson. — Blue River. (594.) 



Erysimum Wheeleri, sp. nov.—3-5° high, erect, unbranched, sparsely 

 covered with closely appressed hairs, which are fixed by the middle 

 (very rarely forked), never 4-parted ; root-leaves, including petiole, into 

 which they gradually taper, 2-4' long, narrowly lance-linear, entire or 

 sub-entire; stem-leaves narrowly lanceolate, sessile, 1-2 J' long, entire; 

 pedicels (in fruit) \-% long; mature pods erect, 1-2' long (in younger 

 pods there are distinct ribs between the angles), canescent; stigma two- 

 lobed, style evident; seeds attached to each side of cell; cotyledons 

 obliquely incumbent ; petals varying from yellow to scarlet, twice as long 

 as sepals, claw % long, nearly filiform, lamina obovate, little over £' long. 



