STUDIES IN THE CRUCIFER X. 131 
tically combined the quadrangular-podded species with this 
genus in naming as Cheiranthus asper the plant which we 
all have known as Erysimum asperum. 
The American species, with which I chiefly have to do, 
are not reducible to defined groups, and consequently need 
not be taken up after any special order of sequence. 
1. C. INSULARIS. Erysimum insulare, Greene, Bull. Torr. 
Club, xiii. 218. Shrub of certain Californian coast islands, 
and one of the nearest relatives of the Old World type- 
species of the genus, Cheiranthus Cheiri, the common Wall- 
flower. 
2. C. caPrTATUS, Dougl. in Hook. Fl. i. 88. Cheiranthus 
asper, Ch. & Schl. in Linnea, i.14,notof Nuttall. Erysimum 
grandiflorum, Nutt. in T. & G. Fl.i.96: E. capitatum, Greene, 
Fl. Fr. 969. High bluffs and low sandhills of the Californian 
and Oregonian seaboard, but by no means a “ saline" plant, 
as the authorship of the Synoptical Flora would make it. It 
never appears in the saline soils of the region, nor even near 
such places. The plant is decidedly perennial, as Nuttall 
said; and by its flattened pods it is one of the more typical 
among the species of Cheiranthus. The flowers, usually of 
a delicate cream-color, vary to sulphur and lemon yellow, 
especially northward at Crescent City, California, and in 
Oregon; and there is a character of the pubescence which I 
do not find mentioned by any writer. Though the stem 
and some leaves show more or less of the simply divided 
and divaricately appressed hairs usual in the genus, the 
lower ampler and less pubescent leaves are more or less 
stellate-pubescent, the hairs being divided into 3 and 4 
branches instead of two. 
3. C. ARENICOLA. Erysimum arenicola, Wats. Proc. Am, 
Acad. xxvi. 194. Also perennial, like the foregoing, but 
Subalpine on the mountains of Washington, and with flat 
lened pods. 
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