1915] | Macbride,— Sisymbrium brachycarpon and Allies — 139 
S. brachycarpon, particularly in the central-southern Rocky Moun- 
tains tends to have on the lower part of the stem a fine stellate puberu- 
lence which persists even after the plant has matured fruit. This 
variation forms part of Sophia intermedia Rydb., some specimens 
having this character being labeled by Dr. Rydberg as belong- 
ing to his species. However, 5. intermedia, as originally described, 
included Montana specimens quite referable to S. brachycarpon 
and entirely i: separable from typical collections of that species from 
the northeastern states. The more southern permanently puberulent 
material, included in the former species by its author, connects the 
latter species with S. canescens on account of its more marked pubes- 
cence. Its leaves, however, definitely ally it to S. brachycarpon. 
By placing a limited interpretation on S. intermedia Rydb., letting it 
include only those plants with the more permanent pubescence, 
it is possible to dispose of a considerable number of collections from 
the Rocky Mountains that otherwise would have to be referred to 
S. brachycarpon or to S. canescens where they would be, in either case, 
decided misfits. I think, however, that the facts will be more clearly 
indicated if this plant is regarded as a variety of its nearer relative 
rather than as a species equally distinct from both. 
There is another variation which, unless treated as a species, has 
been kept as a variety of a plant which is obviously not its nearest 
relative. This is S. incisum Engelm. var. filipes Gray, which has the 
comparatively short clavate pods with the seeds more or less in two 
rows as in the S. canescens group, as pointed out by Dr. Rydberg, 
Fl. of Col. 157 and Mem. N. Y. Bot. Gard.i. 185. In foliage it is not 
unlike S. brachycarpon except the upper leaf-segments tend to become 
elongate. The stems are glabrous or slightly cinereous with a minute 
stellate puberulence. It must, therefore, be regarded as a variety 
of S. brachycarpon rather than of S. incisum, a species well marked 
by its very narrow pods with strictly uniserial seeds. 
The plants here discussed may be summarized as follows. 
Pods very slender; seeds strictly l-ranked in each cell....1. S. incisum. 
Pods clavate or subclavate; seeds more or less 2-ranked in each cell. 
Plant canescent with a soft stellate- or branched-pubescence; pinnules 
shortuand rounded- mion eS UM ce 2. S. canescens. 
Plant green or cinereous below with a fine stellate puberulence; pinnules, 
at least mostly, elongate and slender. 
Leaf-segments of about uniform length; fruiting pedicels usually 
less than 1.5 cm. long. 
Glabrate or stellate-puberulent below when young; more or less 
glandular with simple viscid trichomes toward or quite to 
the base of the stem.............. 3. S. brachycarpon. 
