166 XIII. CRUCIPERiE. Arabis. 



1 . T. GLABRA. Smooth Toxmr Mustard. 



St. erect ; radical lis. petiolate, dentate, with ramose hairs, cauline ones 

 broad-lanceolate, sagittate, hall-clasping, glaucous, smooth; siliqives erect.— 

 Shores of Lake Superior, W. to the Rocky Mts. Naturalized about New 

 E.Q.Yen. Eaton. Stem round, simple, lAf high. Leaves 1—2' long. Siliques 

 2—3' long, very narrow. Flowers pale sulphur-yellow. May. 



y3 1 T. & G. Lvs. all linear-lanceolate and glabrous, radical ones remotely 

 repand-denticulate, cauline entire.— Watertown, N. Y., on rocks. Torrey <^ Gray. 



2. T. BRACHYCARPA. Torr. & Gray. 



Glabrous and glaucous ; radical lvs. spatulate, dentate, cauline ones linear- 

 lanceolate, sagittate and subamplexicaul ; siliques short, linear-oblong ; pedicels 

 pendulous in flower, spreading in fruit.— @ Lake shores, Mich. Stem 1— 2f 

 high, often purplish, as well as the foliage. Flowers rather large, pale purple. 

 Siliques V long, spreading. 



15. arAbis. 



Said to derive its name from Arabia, its native country. 



Sepals erect ; petals unguiculate, entire ; silique linear, compressed ; 

 valves 1 -veined in the middle; seeds in a single row in each cell. — 

 JFls. white. 



1. A. Canadensis. (A. falcata. Michx.) Sickle Pod. 



Cauline lvs. sessile, oblong-lanceolate, narrow at base, pubescent ; pedi- 

 cels pubescent, reflexed in the fruit ; silique subfalcate, veined, pendulous ; 5^5. 

 winged.— 'll On rocky hills. Can. to Ga. W. to Ark. A plant remarkable for 

 its long, drooping pods, which resemble a sickle blade, or rather a curved 

 sword blade. Stem 2— 3f high, slender, round, smooth. Leaves 1—3' long, i 

 as wide ; the lowest early marescent, middle and upper ones sessile or clasping, 

 with narrow bases, remotely denticulate. Flowers small, white. Pods slen- 

 der, flattened, nearly 3' long. Jn. 



2. A. LYRATA. (Sisymbrium arabidoides. Darl.) 



St. and upper lvs. smooth and glaucous ; radical lvs. lyrately pinnatifid, 

 often pilose ; st. branched at base ; pedicels spreading ; siliques erect. — (g) On 

 rocky hills, Can. to Va. Stems often many, united at base, 6—12' high. Root- 

 leaves numerous, rosulate, 1—3' long, i as wide, petiolate, lower stem-leaves 

 pinnatifid or sinuate-dentate, upper ones sublinear and subentire. Flowers 

 middle size. Siliques when mature 1^-2' long, less than 1" wide. Apr. Ma)^ 



3. A. L5DVIGATA. DC. (Turritis tevigata. Muhl.) 



Smooth and glaucous; radical Its. obovate and oblong, tapering to a pe- 

 tiole, dentate, stem lvs. linear-lanceolate, amplexicaul, obtuse, ujrper ones entire ; 

 pedicels about as long as the calyx, erect ; siliques very long, linear, at length 

 spreading and pendulous ; sds. winged. — % In rocky woods and low grounds, 

 Can. to Ark. Stem 1 — 2f high, round, .smooth, simple or branched above. 

 Root-leaves often purplish, f — 1^' long, \ as wide, with acute teeth. Stem- 

 leaves 2 — 5' long, \ as wide, upper ones entire. Flowers in long racemes. 

 Siliques 2—3' long, scarcely 1" wide. May. 



4. A. HiRSUTA. Scop. (Turritis. Linn.) 



Erect, branching ; lvs. mostly dentate, hirsute, radical ones oblong-ovate, 

 tapering to a petiole, cauline ones oval or lanceolate, sagittate ; siliques straight, 

 erect. — (T) Found in low, rocky grounds. Can. to Va. W. to Oregon. Stems 2 

 or more from the same root, round, hairy at base, near a foot high, dividing 

 into very .slender and parallel branches. "Leaves scarcely dentate, sessile, with 

 heart-shaped or arrow-shaped bases, upper ones acute. Flowers greenish- 

 white. Siliques straight, 1 — 2' long. Jn. 



5. A. HETEROPHYLLA. Nutt. 



Nearly smooth ; radical lvs. spatulate, toothed, upper ones linear, sessile, 

 entire; siliqve\oi\g and spreading ; j9g/. linear-oblong, exceeding the calyx. — 

 Near Paris, Me., and the White Mts., N. H. Radical leaves somewhat pilose 

 with simple hairs, upper ones linear, about 2' long, and 1 — 2" wide. Siliques 

 about 3' long. Nuttall. 



