116 CRUCIFERAE. [Vox. II. 
1, Sisymbrium officinale (L.) Scop. 
Hedge Mustard. (Fig. 1696.) 
Erysimum officinale \,. Sp. Pl. 660. 1753. 
Sisymbrium officinale Scop. Fl. Carn. Ed. 2, 2: 26. 
1772. 
Erect, more or less pubescent, or glabrous, 1°— 
3° high, with rigid spreading branches. Leaves 
runcinate-pinnatifid, the lower petioled, the up- 
per nearly sessile; lobes 3-6 pairs and an odd 
one, oblong, ovate or lanceolate, dentate, crenate 
or nearly entire, acutish or obtuse, the lower 
ones often recurved; pedicels 1’’ long, erect in 
fruit; flowers yellow, 114’’ broad, pods 5//—7’” 
long, linear, acuminate, glabrous or slightly 
hairy, closely appressed to the stem; valves with 
a strong prominent midrib. 
In waste places, common throughout our area, 
except the extreme north. Naturalized from 
Europe. Native also of northern Asia. May-—Nov. 
2. Sisymbrium altissimum lL. ‘Tall 
Sisymbrium. (Fig. 1697.) 
Sisymbrium altissimum 1,. Sp. Pl. 659. 1753. 
Sea eg Sinapistrum Crantz, Stirp. Aust. Ed. 2, 
Ceumnartics Pannonicum Jacq. Coll. 1:70. 1786. 
Erect, 2°-4° high, freely branching, glabrous or 
nearly so. Lowest leaves runcinate-pinnatifid, 
petioled, the lobes lanceolate, often auriculate; 
upper leaves smaller, shorter petioled or nearly ses- 
sile, very deeply pinnatifid, the lobes linear or lan- 
ceolate, dentate or entire, often with a narrow pro- 
jection on the lower side near the base; uppermost 
leaves often reduced to linear nearly entire bracts; 
flowers yellowish, about 3’ broad; pedicels 3//-4’/’ 
jong, spreading or ascending, thickened in fruit; 
pods very narrowly linear, divergent, 2’-4’ long, 
%4// wide; valves with a prominent midrib. 
In waste places, Quebec and Ontario to Alberta and 
Missouri, and in ballast at New York. Adventive from 
Europe. A bad weed in the Northwest. Summer. 
PL 
3. Sisymbrium humile Meyer. Low or 
Northern Rock-cress. (Fig. 1698.) 
Arabis petraea Hook. Fl. Bor. Am. 1: 42. 1829. Not Lam. 
Sisymbrium humile Meyer, in Ledeb. Fl. Alt. 3:137. 183r- 
Braya humilis Robinson, in Gray & Wats. Syn. Fl. 1: Part 
1, 141. 1895. 
Perennial, erect, 4/-10’ high, branching below, spar- 
ingly pubescent. Leaves spatulate, or oblanceolate, the 
lower obtuse, 1’—2’ long, narrowed into a petiole, sharply 
dentate or rarely entire, the upper smaller, narrower, 
often acute; flowers white or pink, 114’/-2’’ broad; pedi- 
cels ascending or erect, 2’’-3’” long in fruit; pods nearly 
terete, glabrous, narrowly linear, 6’’-10’’ long, 14’ 
wide; valves finely nerved; style %’ long. 
In rocky places, Anticosti, Willoughby Mountain, Vt., 
near Michipicoten Harbor, Lake Superior, to Alaska and 
Oregon. Species perhaps better referred to the arctic 
genus Braya, as maintained by Dr. B. L. Robinson, July. 
