1909] Fernald,— North American Species of Barbarea 137 
covered by his description varies in the degree to which the pods are 
appressed, but as Rydberg’s description indicates, there is no clear 
line to separate these minor variations. As described by Rydberg his 
B. americana occurs from “Northwest Territory” to Montana and 
Nevada; but the plant is widely distributed in our boreal and mountain 
regions, occurring from Ungava Bay, Labrador, south to river-banks 
and mountain-ravines of northern New England, northwestward to 
arctic Alaska, the Aleutian Islands, and adjacent northeastern Asia, 
and southward in western America to Colorado, and southern Cali- 
fornia. But clearly defined as is this plant, which is so typically : 
species of our boreal flora, it seems to have had but one well established 
“name (excluding the doubtfully published B. gracilis of Nuttall !) 
prior to that assigned to it bv Rydberg. In 1824, Ledebour published 
the Siberian B. orthoceras? with the pedicels of the siliques erect. 
Material of this species collected in Amur by Maximowicz is quite 
identical in basal and cauline leaves, strongly ascending pods, and 
short thick styles with American material which has been determined 
by Dr. Rydberg as B. americana; and there seems no reason why the 
name В. orthoceras Ledeb. should not be taken up for the plant which, 
widely distributed in our boreal and montane regions, extends, like 
so many of our other plants, by way of the Aleutian Islands and 
northwestern Alaska to the northeastern regions of Asia.’ 
In the southern part of its range Barbarea orthoceras is less char- 
acteristic than northward, the siliques tending to be longer, more 
divergent, and somewhat remote instead of strongly ascending or 
appressed and forming a dense slender raceme. Many transitional 
tendencies occur, however, and the longer-podded extreme seems best 
considered a variety of B. orthoceras, standing in the same relation to 
it as B. vulgaris to its var. longisiliquosa. 
Another indigenous species, of unusual interest because of its peculiar 
habit of bearing in the lower part of the primary racemes leafy bracts 
1 Nuttall apparently did not formally publish Barbarea gracilis though it is ascribed 
to him by Torrey & Gray with the remark that ' Mr. Nuttall thinks that the var, В [уаг, 
gracilis from “Oregon "] is a distinct species which he calls B. gracilis. Nuttall’s plant, 
labeled distinctly in his own handwriting “ Barbarea gracilis. B vulgaris, B. gracilis 
DC. Oregon woods,” is in the Gray Herbarium and has been re-labeled by Dr. Rydberg 
“В. americana Rydb. P. A. К.” 
? Ledeb, Hort. Dorp.(1824) and Fl. Ross i. 114 (1841). 
3 It is probable that Barbarea orthoceras occurs across the colder regions of Eurasia to 
arctic Europe. Rouy & Foucaud, discussing the European species say: “La forme des 
régions arctiques est le B. orthoceras Ledeb."; and Nyman's Conspectus and the Index 
Kewensis treat Fellman's B. stricta from Lapland as B. orthoceras. 
