CRUCIFERjE. 



39 DENTARIA. 



4. A'RABIS. 



Silique compressed, linear; valves one-nerved in the mid- 

 dle; seeds in a single row in each cell. 



Said to derive its name from Arabia, its native country. A genus well 

 distinguished by its linear, compressed siliques and flat valves. Two of the 

 opposite sepals larger and protuberant at base. Petals a little shorter than 

 calyx, entire. Flowers generally white. 



1. A. CaNADE'NSIS. L. a. falcata. .¥, 

 Stem haves sess\\e, oblong-lanceolale, narrow at base, pubescent; pedicels 



pubescent, reflexed in the fruit; silique sub-falcate, nerved, pendulous. On 

 rocky hillsL A plant remarkable for its long drooping pods, which resemble 

 a sickle blade, or rather a curved sword blade. Stem 2 or 3 feet high, slen- 

 der, round , smooth. Loaves scattered, slightly toothed, the lower ones some- 

 what clasping, upper sessile, with narrow bases. Flowers small, white. Pods 

 slender, flattened, nearly 3 inches long. June, Per. Sickle-pod. 



2. A. lyra'ta. 



Stem and upper leaves smooth and glaucous ; radical lea.ves lyrate-pinnati- 

 fid, often pilose; stern branched at the base; pedicels spreading; siltque erect. 

 On rocky hills. Stems many, united at base, 8 iirches high. Stem-leaves 

 narrow, obtuse, taperino- at basje, the upper ones entire, lower ones with a few 

 teeth, radical ones stalked, and lyrate-toothed at base. Flowers middle size, 

 white. April— July. Bien. 



3. A. LEVIGA'TA. Dc. Turritis. L. 

 Stemleaves linear oblong, sagittate, smooth, lower ones subdentate, radical 



ones obovate ; pedicels erect; siliques very long and narrow, at length pendu- 

 lous. On rocky hills. Stem 2 feet high, simple, round, smooth, its leaves with 

 remote amd minute teeth. Flowers vv'hite. Pods 1 J inches long. May, Per. 



4. A. hirsu'ta. 



Erect, branching ; leaves mostly dentate^ hirsute ; radical ones oblong-oyate, 

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

 erect. IPound at Windsor, Vt. Stems two or more from the same root, round, 

 hairy at base, near a foot high, dividing into very slender and parallel branch- 

 es. Leaves scarcely dentate, sessile, with heart shaped or arrow-shaped 

 bases, upper ones acute. Flowers white. June. Hairy Cress. 



5. DENTA'RIA. 



Silique lanceolate, with flat, nerveless, revolute valves, 

 opening elasticallj; placentae not winged; funiculus dilated. 



Lat. dcHS, a tooth; the rhizoma is furnished v^ith projecting angles which 

 resemble the molar teeth of animals. Cal. converging. Silique dissep. thick 

 and fungous-like. Stig. emarginate. Seeds in a single row, ovate, 



1. D. diphy'lla. 



Stem two-leaved ; leaflets ternate, subovate, unequally and incisely dentate ; 

 rhizoma dentate. In woods and wet meadows. Stem about a foot high, round, 

 smooth, with 2 nearly opposite, ternate leaves above the middle. Leaflets on 

 very short stalks, the lateral ones oblique, all with rounded, mucronate, une- 

 qual teeth. Flowers racemed, large, white; the petals much larger than th» 



