Genus 34. 



MUSTARD FAMILY. 



10. Cardamine rotundifolia Michx. 



Round-leaved or American 



Water-cress. Fig. 2092. 



Cardamine roliiiulifolia Michx. Fl. Bor. 

 Am. 2 ; 30. 1 80 J. 



Perennial, weak, ascending or decum- 

 bent, forming long stolons; roots fibrous. 

 Basal leaves and stem-leaves similar, tbe 

 lower petioled, the upper sessile, ovate, 

 oval, or orbicular, obtuse, undulate angled 

 or entire, thin, the base rounded, trun- 

 cate or cordate; pedicels 4"-l2" long; 

 flowers white. 2"-^" broad ; pods linear, 

 7"-8" long, i" wide, pointed ; style i" 

 long; stigma minute; seeds oblong. 



In cold springs. New York to Ohio, Mis- 

 souri, North Carolina and Kentucky. As- 

 cends to 3500 ft, in Virginia. Mountain 

 water-cress. May-June. 



35. DENTARIA [TonFn.] L. Sp. PI. 653. 1753. 



Perennial herbs, with fleshy horizontal scaly or toothed rootstocks, erect mostly un- 

 branched stems leafless below, 3-divided or palmately laciniate petioled leaves, and corym- 

 bose or short-racemose, white, rose-colored or purple flowers. Petals much longer than the 

 sepals. Stamens 6. Style slender. Silique linear, flat, elasticallj' dehiscent from the base, 

 its valves nerveless or with a faint midnerve ; stipe none. Seeds in I row in each cell, thick, 

 oval, flattened, wingless ; cotyledons thick, nearly or quite equal, accumbent. [Greek, tooth, 

 from the tooth-like divisions of the rootstock.] 



.\bout 15 species, natives of the northern hemisphere. Besides the following, some 7 others 

 occur in the western parts of North America. The species are called Pepper-root and Tooth-root, 

 from their pungent and toothed rootstocks. Type species: Dcntaria fcntapliyllos L. 



Basal leaves and stem-leaves similar. 



Leaf-divisions lanceolate or oblong, lobed or cleft ; joints of the rootstock readily separable. 



I. D. laciniata. 

 Leaf-divisions ovate or ovate-oblong, crenate or lobed. 



Stem-leaves 2, opposite, or close together ; rootstock continuous. 2. D. diphylla. 



Stem-leaves 2-5, alternate : rootstock jointed. 3. D. maxima. 



Divisions of the stem-leaves linear or lanceolate; those of the basal leaves ovate, much broader; 

 joints of the rootstock readily separable. 4. D. hefcrophylla. 



I. Dentaria laciniata Muhl. Cut-leaved 

 Toothwort or Pepper-root. Fig. 2093. 



D. laciniata Muhl.; Willd. Sp. PI. 3; 479- 1800. 

 Cardamine laciniata Wood, Bot. & Fl. 38. 1870. 

 Dentaria furcata Small, Fl. SE. U. S. 480. 1903- 



Erect, pubescent or glabrous, 8'-is' high ; 

 rootstock deep, tubercled, jointed, the joints 

 readily separable. Leaves all petioled, 2-5 

 broad, those of the stem generally 3 and ap- 

 proximate or verticillate, rarely distant, 

 3-partcd nearly to the base ; divisions lanceo- 

 late, linear or oblong, the lateral ones often 

 deeply 2-cleft, all incisely toothed or lobed, or 

 the lateral ones entire; basal leaves similaf, 

 rarely developed at flowering time ; pedicels 

 stout, 8"-io" long in fruit ; flowers 7"-9" 

 broad, white or pink; pods linear, ascending, 

 I'-ij' long. 



In moist or rich woods, Quebec to Florida, west 

 to Minnesota, Kansas and Louisiana. Purple- 

 flowered toothwort. Crow-foot. Crow-toes. April- 

 June. 



