Annual, biennial or perennial, mainly erect and branching herbs, more or less pubescent or hoary, with 2-branched hairs, the leaves simple, entire, toothed or lobed. Flowers yellow. Siliques elongated, linear, 4-angled or rarely terete; valves strongly keeled by a prominent midvein. Stigma lobed. Seeds oblong, in 1 row in each cell, marginless or narrowly margined at the top; cotyledons incumbent. [Greek name from similarity of this genus to Cheiri Adans.]

A genus of about 90 species, natives of the north temperate zone, most abundant in eastern Europe and central Asia. In addition to the following, several others are found in the Rocky Mountains and on the California coast. Type species: Cheirinia cheiranthoides (L.) Link.

Flowers 2"-4" high.

Pedicels slender, spreading; pods very narrow, 6"-12" long.

1.

C. cheiranthoides.

Pedicels stout, short.

Perennial; native; pods ascending.

2.

C. inconspicua.

Annual; introduced; pods spreading.

3.

C. repanda.

Flowers 8"-12" high, conspicuous.

4.

C. aspera.

25 Cheirinia Link Enum Hort Berol 2 170 1820 397

1. Cheirinia Cheiranthoides (L.) Link. Worm-Seed Or Treacle Mustard

Fig. 2055

Erysimum cheiranthoides L. Sp. Pl. 661. 1753.

Cheirinia cheiranthoides Link, Enum. Hort. Berol. 2: 170. 1820.

Cheiranthus cheiranthoides Heller, Cat. N. A. Pl. 4. 1898.

Erect, minutely rough-pubescent, branching, 8'-2° high. Leaves lanceolate or oblong-lanceolate, 1'-4' long, acutish or obtuse, entire or slightly dentate, tapering at the base into a short petiole or the upper sessile; pedicels slender, spreading or somewhat ascending, 3"~4" long in fruit; flowers about 2 1/2" high; pods linear, obtusely 4-angled, glabrous, 6"-12" long, less than 1" broad, nearly erect on slender spreading pedicels; valves strongly keeled; styles 1/2" long.

Along streams and in fields, Newfoundland to New Jersey, Pennsylvania, Tennessee and Missouri, west to the Pacific Coast. Appears in some places as adventive. Also in northern Europe. Tarrify. June-Aug.

3. Cheirinia Inconspicua (S. Wats.) Britton. Small-Flowered Prairie-Rocket

Fig. 2056

Erysimum parviflorum Nutt.; T. & G. Fl. N. A.

1: 95. 1838. Not Pers. Erysimum asperum var. inconspicuum S. Wats.

Bot. King's Exp. 24. 1871. E. inconspicuum MacM. Met. Minn. 268. 1892. Erysimum syrticolum Sheldon, Bull. Torr. Club 20: 285. 1893.

Perennial, roughish-puberulent or canescent, stem erect, 1°-2° tall, simple or sparingly branched. Leaves oblanceolate or linear, 1'-3' long, obtuse, entire or dentate, the upper sessile, the lower slender-petioled; flowers about 4" high and broad; pedicels stout, about 2" long in fruit, ascending; pod narrowly linear, 3/4'-2 1/2' long, about 1" wide, minutely rough-puberulent, narrowly ascending or erect; style very stout, 1/2"-1" long.

In dry soil, Ontario to Manitoba, British Columbia and Alaska, south to Kansas, Colorado and Nevada. Adventive farther east. July-Aug.

3 Cheirinia Inconspicua S Wats Britton Small Flowe 398

3. Cheirinia Repánda (L.) Link. Repand Cheirinia

Fig. 2057

Erysimum repandum L. Amoen. Acad. 3: 415. 1756.

Cheirinia repanda Link, Enum. Hort. Berol. 2: 171. 1820.

Annual, pubescent, about 1o high, often much branched. Leaves lanceolate to oblong-lanceolate, 1 1/2'-3 1/2' long, repand-denticulate or the lower ones coarsely toothed; flowers 3"-4 1/2" high; pedicels stout, 2"-3" long; style short and stout; pods widely spreading, 1 1/2'-3 1/2' long, about 1" thick.

Waste and cultivated grounds, Ohio to Kansas and Arizona, and in ballast at eastern seaports. Adven-tive or naturalized from Enrope. May-July.

3 Cheirinia Rep Nda L Link Repand Cheirinia 399

4. Cheirinia Áspera (Dc.) Britton. Western Wall-Flower. Yellow Phlox

Fig. 2058

Erysimum lanceolatum Pursh, Fl. Am.

Sept. 436. 1814. Not R. Br. 1812. Erysimum asperum DC. Syst. 2: 505.

1821. Erysimum arkansanum Nutt.; T. & G.

Fl. N.A.I:9s. 1838.

Rough-pubescent or hoary, 1°-3° high, simple or branching above. Lower leaves lanceolate or linear, tapering into a petiole, dentate or sometimes entire, mainly acute; upper leaves smaller, sessile or nearly so, entire or rarely toothed; flowers orange-yellow, large and showy, 6"-12" high and nearly as broad; pedicels stout, spreading, 2"-3" long in fruit; pods linear, rough, 1 1/2'-4' long, nearly 1" wide, 4-sided; styles short, thick.

In open places, Newfoundland and Quebec; Ohio and Illinois to Texas, Saskatchewan, Colorado and New Mexico. The eastern plant generally has broader leaves than the western. Prairie-rocket. Orange-mustard. May-July.

4 Cheirinia Spera Dc Britton Western Wall Flower Y 400