32 crucifer^:. (mustard family.) 



2. I>. maxima, Nutt. Rootstock interrupted, forming a string of toothed 

 tubers ; stem-leaves (2 - 7 ) mostly 3 and alternate ; leaflets 3, ovate, obtuse, coarsely 

 toothed and incised, often 2-3-cleft. (D. laciniata, var. S., Torr. §■ Gr.) — W. 

 New York, and Penn., Nuttall ! Watertown, New York, Dr. Crawe ! May. — 

 Stem 10' -2° (Nutt.) high: raceme elongated. Flowers larger than in No. 1, 

 purple. Joints of the rootstock l'-2' long, £' thick, starchy. The leaves are 

 intennediate between No. 1 and No. 3. 



3. I>. lacilliafa, Muhl. Rootstock necklace-form, consisting of a chain 

 of 3 or 4 nearly toothless oblong tubers ; stem-leaves 3 in a whorl, 3-parted ; the 

 leaflets linear or lanceolate, obtuse, irregularly cut or cleft into narrow teeth, the 

 lateral ones deeply 2-lobed. — Eich soil along streams, W. New England to 

 Wisconsin and Kentucky. May. — A span high : raceme scarcely longer than 

 the leaves. Flowers pale purple. Root-leaves much dissected. 



4. I>. heteropbylla, Nutt. Rootstock necklace-form, obscurely toothed ; 

 stem-leaves 2 or 3, small, alternate, 3-parted, the leaflets lanceolate and nearly entire , 

 root-leaves of 3 round-ovate obtuse somewhat toothed and lobed leaflets. — West- 

 ern Pennsylvania, Virginia, and Kentucky. May.— A span high, slender: 

 stem-leaves 1' long. Flowers few, purple. 



5. CARD AMINE, L. Bitter Cress. 



Pod linear, flattened, usually opening elastically from the base ; the valves 

 nerveless and veinless, or nearly so. Seeds in a single row in each cell, wing- 

 less; their stalks slender. Cotyledons accumbent.— Flowers white or purple. 

 (From KapSapov, an ancient Greek name for Cress.)— Runs into Dentaria on 

 the one hand, into Arabis on the other. 



* Root perennial : leaves simple or 3-foliolate. 



1. C. rhomboidea, DC. (Spring Cress.) Stems upright, taberifer- 

 ous at the base; stems simple; root-leaves round and rather heart-shaped; lower 

 stem-leaves ovate or rhombic-oblong, somewhat petioled, the upper almost lan- 

 ceolate, all somewhat angled or sparingly toothed ; pods linear-lanceolate, point- 

 ed with a slender style tipped with a conspicuous stigma ; seeds round-oval. — 

 Wet meadows and springs ; common. Flowers large, white. April -June. 



Var. purpurea, Torr. Lower (4' -6' high) and slightly pubescent; 

 leaves rounder; flowers rose-purple, appearing earlier.— Along streams in rich 

 soil, W. New York to Wisconsin. 



2. C. rotMiadifolia, Michx. (American Water-Cress.) Stems 

 branching, weak or decumbent, with creeping runners; root fibrous; leaves all much 

 alike, roundish, somewhat angled, often heart-shaped at the base, petioled, the 

 lowest frequently 3-lobed or of 3 leaflets ; pods linear-awl-shaped, pointed with 

 the style; stigma minute; seeds oval-oblong. (Sill. Journal, 42. p. 30.) — Cool, 

 shaded springs, Penn., and southward along the mountains. May, June.— 

 Leaves with just the taste of the English Water-Cress. Runners in summe- 

 10-3° long. Flowers white, smaller than in No. 1. 



3. C. bellMifdlia, L. Dwarf (2' -3' high), tufted; leaves ovate, en- 

 tire, or sometimes 3-lobed (4" long), on long petioles ; pods upright, linear ; shfU 



