Cheiranthus. XIII. CRUCIFER^, 1G9 



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

 Flowers small, yelkm-, terminating ihe raceme, wliicli becomes 1 — 21' long and 

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



2. S. Thaliana. Gay. (Arabis, Linn.) Thaliaii llah^e Mustard. 

 Lvs. subdentate and pilose, vY/r/Zcrt/ tines numerous and petiolate, oblong, 



cauline ones lanceolate ; cal. much shorter than the pedicels ; silu/vcs ascending, 

 twice longer than the pedicels.— (i) 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, c'iliate, 

 sessile, 6—12" by 1—3". Pedicels spreading, 3—5" long. Flowers small, 

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



3. S. TER^s. T. & G. (Cardamine. Mickx.) 



St. erect, branched ; lvs. 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. 



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

 tate or obtuse ; pet. about equaling the calyx ; silitpies 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. 



Gr. Epvu), to cure ; from its salutary medicmaJ properties. 



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

 in a single series ; cotyledons oblong, Oj|. 



1. E. CHEIRANTHOiDES. 



Pubescence minute, appressed, branched ; lvs. 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. Yellmo Phlox. False WaU-Flower. 



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

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

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

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

 of Scioio, Sullivant. 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 khcyry, the name of a certain plant, and Gr. ai/^of , 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. HESPERiDoiDES. T. & G. (Hcspcris pinnatifida. Michx.) 

 Glabrous; lower lvs. lyrate-pinnatifid, «;;^?e/- lanceolate, attenuate at base, 

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

 pet. obovate-spatulate, obtuse ; silique terete ; stig. capitate ; 5^5. margined. — 

 % 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. 



