CHEIRANTHUS. XIII. CRUCIFER^. 169 



ment largest. Upper leaves in 3 lanceolate segments placed at right angles. 

 Flowers small, yellow, terminating the raceme, which becomes 1 2f long and 

 environed by the appressed, sessile pods. Jn. Sept. Medicinal. 



2. S. THALIANA, Gay. (Arabis. Linn.') Thalian Hedge Mustard. 

 Lvs. subdentate and pilose, radical ones numerous and petiolate, oblong, 



cauline ones lanceolate ; col. much shorter than the pedicels ; siliques ascending, 

 twice longer than the pedicels. - Rocks and sandy fields, Vt. to Ga. W. to 

 Ky. Stem 4 12' high, erect, with slender, erect branches, striate, pilose, often 

 purple at base. Root leaves rosulate, 1 2' long ; cauline denticulate, ciliate, 

 sessile, 612" by 1 3". Pedicels spreading, 35" long. Flowers small, 

 white. Siliques slender, straight, 7 10" long. Styles scarcely any. May. 



3. S. TERES. T. & G. (Cardamine. Michx.} 



St. erect, branched ; Ivs. all somewhat lyrately pinnatifid ; siliques short, 

 linear, acuminate, on very short peduncles ; II. Shores of Lake Cham- 

 plain, Vt. Plant about 8' high, slightly scabrous with very short hairs. Sili- 

 ques erect, terete, 4" in length, beaked with the short, slender style. Seeds 00. 



4. S. CANESCENS. Nutt. 



Lvs. bipinnately divided, canescent, lobes oblong or lanceolate, subden- 

 tate or obtuse ; pet. about equaling the calyx ; siliques oblong-linear, shorter 

 than the pedicels. Arctic Sea to Flor. Plant 1 2f high, often nearly 

 smooth. Leaves about 3' long, sessile, segments 5 7 pairs, finely divided. 

 Fls. very small. Siliques often erect, on spreading pedicels. Variable. 



20. ERYSIMUM. 



Gl'. cpvw, to cure ; from its salutary medicinal properties. 



Calyx closed ; siliques columnar, 4-sided ; stigma capitate ; seeds 

 in a single series ; cotyledons oblong, Ojj. 



1. E. CHEIRANTHOlDES. 



Pubescence minute, appressed, branched ; Ivs. lanceolate, denticulate or 

 entire ; silique erect, spreading, twice longer than the pedicels ; stig. small, 

 nearly sessile. By streams and in wet grounds, U. S. and Can., not com- 

 mon. Stem erect, 1 2f high, often branched, and, with the leaves, scabrous. 

 Leaves acute at each end, 1 2' long, as, wide. Flowers small, yellow, in 

 long racemes. Siliques ' to near 1' in length, linear, and somewhat spread- 

 ing. Jl. 



2. E. ARKANSANUM. Nutt. Yellow Phlox. False Wall-Flower. 



Scabrous, with an appressed pubescence ; st. simple ; Ivs. linear-lanceo- 

 late, remotely dentate, sessile, lower ones runcinate-toothed ; inflorescence race- 

 mose, corymbed at summit; siliques long, 4-angled, suberect; stig. capitate. 

 () A fine plant with large, showy flowers, resembling the wall-flower. Banks 

 of Scioto, SuUivant. Arkansas, Nuttall. Bluffs of the Wabash ! Wood. 111. 

 Mead! Stem 1 3f high, slender. Leaves 2 3' by 3 6". Sepals straw-color. 

 Petals large, bright orange-yellow. Siliques 3' long. Jn. Jl. 



21. CHEIRANTHUS. 



Arabic kheyry, the name of a certain plant, and Gr. avSos, flower. 



Calyx closed, 2 of the sepals gibbous at base ; petals dilated ; 

 silique terete or compressed ; stigma 2-lobed or capitate ; seeds flat, 

 in a single series, often margined, 0=. 



1. C. HESPERioolDES. T. & G. (Hesperis pinnatifida. Michx.} 

 Glabrous ; lower Ivs. lyrate-pinnatifid, upper lanceolate, attenuate at base, 

 unequally and sharply serrate-dentate, acuminate ; pedicels as long as the calyx ; 

 pet. obovate-spatulate, obtuse; silique terete; stig. capitate; sds. margined. 

 7J. Penn. to 111. ! S. to Ark. Stem slender, furrowed, 2 3f high. Leaves thin, 

 3 5' long, as wide, those of the stem scarcely petiolate. Racemes terminal 

 and axillary. Calyx shorter than the claws of the violet-colored petals. Siliques 

 torulose, 15 20" long ; seeds oblong, plano-convex, with a narrow border. 

 May, Jn. 



