Cheiranthus. XIII. CRUCIFERjE. 169 



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

 Flowers small yellow, terminating the raceme, which becomes 1— 2f lon/and 

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



2. S. Thaliana. Gay. (Arabis. Linn.) Thalian Heds:e Mustard 

 Lvs. subdentate and pilose, radical ones numerous and petiolate oblon? 



•auhne ones lanceolate ; cal. much shorter than the pedicels ; silioms ascendini' 

 wice 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 c'iliate 

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

 white. Sihques 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 ; 11.—® Shores ol 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. 



Lms. 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. 



Gt. cpvoi, to cure ; from its salutary medicinal properties. 



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

 in a single series ; cotyledons oblong, 0||. 



1. E. CHEIRANTHOlDES. 



Pubescence minute, appressed, branched ; h's. lanceolate, denticulate or 

 entire ; silique erect, spreading, twice longer than the pedicels ; slig. 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, J as wide. Flowers small, yellow, in 

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

 ing. Jl. 



2. E. Arkansanum. Nutt. Yellmn Phlox. False Wall-Flo^oer. 



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

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

 mose, corpnbed at summit ; siliques long, 4-angled, suberect ; sii<^. capitate. — 

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

 of Scioio, SjiUivant. Arkansas, Nuttall. Bluffs of the Wabash ! Wood. Ill, 

 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. av^o^, 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. HESPERiDolDES. T. &G. (Hesperis piimatifida. Michx.) 

 Glabrous; lover Ivs. lyrate-pinnatifid, «/;;«;■ lanceolate, attenuate at base, 

 unequally and sharply serrate-dentate, acuminate; jiediccls as long asthecaly.x; 

 fcl. obovate-spatulate, obtuse; siliqjic terete; s,'?v. capitate; sds. 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. 

 Mav, T^;. 



