ORDER 11. CRUCIFERJ3. 37 



4. ARABIS, L. ROCK-CRESS. Sepals mostly erect , silique linear, com- 

 pressed ; valves plane, each with 1 or 3 longitudinal veins, seeds in a sin- 

 gle row in each cell, mostly margined, cotyledons accumbent or oblique. 

 Flowers white. Figs. 336, 506. 



* Leaves (all or at least the radical) pinnatifld. Stems clustered Nos. 1, 2, 3 



* Leaves all undivided, toothed or entire, often clasping.. (a) (Exotic. No. 10.) 



a Siliques short (6 12") and straight. Sds. not winged. Stems clustered.. Nos. 4, 5 

 a S'.uque* longer (12'), straight or curved. Sds. not winged. St. simple. .Nos. 6. 7 

 a h: aques .ong V 3'), curved, pendent. Seeds winged Nns. 8, 9 



1 A LiUdoviciana Meyer. All the leaves pinnatifld or pinnate, smoothish ; stems 



branched at base ; siliqnes ascending ; seeds bordered. (T) South. 6 KX. March. 



2 A. lyrata L. Upper leaves smooth, linear, entire ; radical leaves lyrately pinnatifld, 



often pilous ; st. branched at base ; pedicels spreading ; siliqnes erect, peeds not bor- 

 dered, obliquely o. Hills, Can. to Va. 612'. Pods If- 2'. Pet. 3" long. Apr.,Mav. 



3 A. petrsea Lam. Upper leaves linear, entire, minute, radical pinnatifld, very smai! ; 



steins clustered; pods ascending (1 1JO; seed? bordered, =-o. it Rocks (Green- 

 wich), Ct., Vt., O., Mich. 6 12'. Flowers white or roseate. June. 



4 A. Tlialla.ua L. St. clustered, erect ; Ivs. pilous, oblong, nearly entire ; pet. twice 



longer than calyx ; pcds erect, squarish (9") ; seeds obliquely | o . (a) Fields, Vt. to 111. 

 and Car. (Wayne Co., N. Y. Hankenson.) 4-12'. Fls. small. May. (Sisymbrium, Gay.) 



5 A. deiitata T. & G. Stems clustered, diffuse ; Ivs. oblong, sharply toothed ; petals' 



hardly longer than the calyx ; pods spreading. (I) N. Y. to Mo. If. Fls. small. May. 



6 A. pateiiB Sull. Erect, pubescent ; cauline leaves coarsely toothed ; siliques spread- 



ing and curved upward, beaked with a distinct style, (a) O. to Tenn. 1 2f. May. 

 1 A. hlrsuta Scop. Erect, hirsute; radical leaves oblong-ovate, cauline lanceolate, 

 sagittate-clasping, entire or toothed ; siliques straight, erect ; style none. @ Can. to 

 Va., and W. 1 2f. June. 



8 A. Ijevlgata DC. Tall, glaucous, smooth ; stem leaves linear-lanceolate and linear, 



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

 and pendulous. @ Can. to Tenn., and W. 2f. Pod 3'. May. 

 ft. minor (Porter). Plant smaller, 1015', with the Ivs. sessile not clasping. Penn 



9 A. Canadeitsls L. Sickle-pod. Tall, pubescent ; stem leaves lanceolate, pointed 



both ways, sessile ; silique subfalcate, veined, pendulous. @ Rocky hills. 2 3f. 

 Petals small, but twice longer than sepals. Pods 3'. May, June. 



10 A. ALPINA. Erect, 8 K', hoary with stellate hairs ; Ivs. oblong, with slender teeth, 

 clasping; fls. showy, pure wh., in many little long-stalked corymbs. Alps. Mar. May. 



6. CARDAMINE, L. BITTER CRESS. Calyx a little spreading. Sil- 

 ique linear or lanceolate, with flat, veiniess valves narrower than the dis- 

 sepiment, and often opening elastically from the base. Stigma entire 

 Seeds not margined, = o . Flowers white or purple. 



$ DENTAKIA. Pod lance-linear. Rhizome thickish, knotted. Stem with 2 or 3 palmated 

 leaves near the middle. Flowers large, corymbed ...(*) 



* Loaves of the stem subopposite or subverticillate Nos. 1, 2. 3 



* Leaves of the stem alternate Nos. 4. 5 



| CARDAMINE. Pod linear. Root tuberous or fibrous. Leaves alternate... it) 



t Leaves pinnate, with many leaflets Nos. ti, 'i 



t Leaves simple or partly ternate. ..(a) 



a Siliques pointed with a slender style. In low, wet grounds Nos. 8. S 



a Siliqnes tipped with the sessile stigma. In high mountains Nos. 10, li 



1 C. dipli j'lla. Stem 2-leaved ; leaflets subovate ; rhizome continuous, toothed. 

 y. Damp woods, Can. to Car. If. Leaves 3-parted, nearly opposite. Root-stock 

 pungent, aromatic. Mav 



