232 ORDER 13. CRUCIFERyE. 



Siliques when mature l 2' long, 1" wide, tipped with a short style. Cotyledons 

 obliquely 0= or nearly Oj. Apr., May. 



ji. A variety (A. PETR^A Lam. ?) has very slender, upright stems, smooth, a 

 few small, incised root-lvs., few linear stem-lvs. and cotyledons wholly 0=;. 

 Shores of the great lakes (Ohio), Can. 



3 A. Thaliana L. MOUSE-EAR CRESS. Sts. branched at base, erect; Ivs. pilous, 

 oblong, nearly entire ; petals twice longer than calyx; pods erect, squarish. @) Bocks 

 and sandy fields, Vt. to 111. and Car. Whole plant pubescent with stellate-hairs. 

 St. several from the same root, erect, simple, slender, 4 12' high. Root-lvs. 

 rosulate, petiolate, 1 2' long, cauline expressed, an inch long, base somewhat 

 clasping. Pis. small, white. Pods 68" long. "Cotyledons obliquely 0|. May. 

 Eur. (Sisymbrium, Gay.) 



4 A. dentata Torr. & Gr. Sts. branched at base, diffuse; Ivs. roughish-downy, 

 ly toothed; petals hardly longer than calyx', pods spreading. (Ti 

 River banks, N. Y. to Mo. Plant scabrous with stellate hairs. Sts. decumbent, 



obloug. sharply toothed; petals 



a foot high. Root-lvs. 2' long by f ; cauline half-clasping with an auriculate 

 base, all very obtuse and irregularly toothed. Fls. small, whitish. Pods very 

 Blender, 1' long. May. 



5 A. patens Sullivant. Erect, Quiescent; cauline Ivs. coarsely toothed ; siliques 

 spreading and curved upwards, beaked with a distinct style. Rocky banks of tho 

 Scioto, 0. (Sullivant), and southward. Sts. 1 2f high. Root-lvs. rosulate, petio- 

 late ; stom-lvs. oblong-ovate or linear, auriculate-clasping. Fls. rather large (5 6" 

 broad), white. Pods nearly 2' long. May. 



6 A. hirsiita Scop. Erect, hirsute ; radical Ivs. oblong-ovate, tapering to a pe- 

 tiole, caulino oval or lanceolate, sagittate-clasping, entire or toothed ; siliques 

 straight, erect ; sty. none. Found in low, rocky grounds, Can. to Va., W. to 

 Oregon. Sts. 2 or more from the same root, round, hairy at base, near a foot 

 high, slender and parallel. Lvs. scarcely dentate, sessile, with heart-shaped or 

 arrow-shaped bases, the upper acute. Fls. greenish -white. Siliques 1 2' long. Jn. 



7 A. laevigata DC. Tall, glaucous, smooth; stem-lvs. linear-lanceolate, and 

 linear, sagittate-clasping, the upper entire ; siliques very long, linear, at length 

 spreading and pendulous. ^- In rocky woods and low grounds, Can. to Tenn. 

 and westward. St. 2f high, round, simple, or branched above. Root-lvs. often 

 purplish, obovate and oblong, petiolate, !' long, as wide, with acute teeth. 

 Stem-lvs. 3 5' long and very narrow. Fls. erect, greenish, tho petals hardly 

 longer than the calyx. Siliques 3' long, scarcely 1" wide. May. 



8 A. Caiiadensis L. SICKLE POD. Tall, pubescent; stem Ivs. lanceolate, pointed 

 both ways, sessile ; silique subfalcate, veined, pendulous. ^j- On rocky hills Can. 

 to Ga., W. to Ark. A plant remarkable for its long, drooping pods which resem- 

 ble a sickle-blade, or rather a scythe. St. 2 3f high, slender, round, smooth. 

 Lvs. 3 5' long, J as wide, the lowest early marescent, middle and upper ones 

 sessile or clasping, with narrow bases, remotely denticulate. Fls. small, the nar- 

 row, white petals twice longer than the calyx. Pods slender, flattened, 3' long. 

 May, Jn. 



8. CHEIRANTHUS, L. WALL FLOWER. (Arabic kheyry,t\\e name 

 of a certain plant, and Gr. avOog, 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 ). 

 Garden perennials, mostly European. Lvs. undivided. 



C. Cheiri L. St. somewhat shrubby and decumbent at base ; Ivs. entire or 

 slightly dentate, lanceolate, acute, smooth ; branches angular ; petals obovate ; 

 siliques erect, acuminate. 'M- From S. Europe. A popular garden flower, ad- 

 mired for its agreeable fragrance, and handsome corymbous clusters of orange 

 or yellow flowers. Plant about 2f high. Jn.f 



9. LEAVENW6RTHIA, Torr. (Named for Dr. Leavenworth, the 

 discoverer.) Calyx rather erect ; petals cuneate, retusc or truncate ; 



