STUDIES IN THE CRUCIFERS. 137 
reduce the species so long as it is not shown that the strong 
characters assigned do not exist. 
16. C. NIvVALIS. Erysimum asperum, var. pumilum, Porter 
& Coulter, Fl. Colo. 8, not Erysimum pumilum, Nutt. Low 
multicipitous perennial, bearing several separate tufts of 
leaves and as many short flowering stems on a branching 
crown or caudex: herbage green, but not without some of 
the usual completely 2-parted and closely appressed pubes- 
cence: leaves linear or narrowly lanceolate, mostiy entire: 
racemose stems only 2 to 6 inches high, commonly simple, 
often floriferous almost throughout: flowers often $ inch 
long, but not proportionately broad, the claw of the petals 
being out ofall proportion to the lamina; calyx very strongly 
cordate at base: pods suberect, almost terete, taper-pointed. 
Peculiar, so far as known, to subalpine heights of the 
Colorado Rocky Mountains; in later catalogues, and in all 
the herbaria, taken for Nuttall's E. pumilum, probably for 
no better reason than that the name befits the plant; but 
Nuttall never saw this, nor anything much like it. A mere 
analogue of the subalpine C. perennis of the Sierra Nevada, 
but in nowise closely related to it, as the great differences 
in habit and floral characters clearly indicate. 
It may be a red-flowered form of this which, in Porter & 
Coulter's Flora, has been taken to represent Hesperis Pallasii ; 
but of this I am not certain. However, a plant of southern 
Colorado, with very beautiful rose-red corollas, I wish to 
name as a variety AMŒNUS of C. nivalis. Of this variety I 
have seen no specimens that seem to have a branched caudex, 
or to be of more than biennial duration; and, if I mistake 
not, it isa plant of much lower than alpine or subalpine 
elevations. Typical C. nivalis is often found far above tim- 
ber-line and truly alpine; and it flowers even the second 
or third year from the seed, in which state, it would easily 
pass for a biennial, in the herbarium. Its large flowers are 
of a rather light yellow. 
