66 CRUCIFER^E. (MUSTARD FAMILY.) 



3 lanceolate or linear-oblong somewhat toothed (sometimes incised or 2-cleft) leaflets; 

 root-leaves of 3 rounded or cuneate-ovate incised leaflets ; petals purple. — Perm, 

 (near Philadelphia, Dr. Diffenbaugh) and Washington (Bebb) to Kentucky and 

 southward. April, May. 



4. D. laeiniata, Muhl. Rootstock as in the last ; stem-leaves 3 in a whorl, 3- 

 parted ; the leaflets linear or lanceolate, irregularly cut or cleft into prominent nar- 

 row teeth, the lateral ones deeply 2-lobed; root-leaves similarly dissected; petals 

 pale purple or nearly white. — Rich soil along streams, W. New England to 

 Wisconsin and Kentucky. April, May. 



5. D. multifida, Muhl. More slender and delicate than the last; root- 

 stock similar; stem-leaves 3 or sometimes 2, alternate, opposite, or whorled, finely 

 2 - 3-ternately divided, or the subdivisions parted, into very narrowly linear lobes ; 

 root-leaves similarly 3 - 4-ternately divided; flowers (4-7) white. — Southern 

 Kentucky (doubtless) and southward. — This appears to pass into No. 4; and 

 all these species except the first probably run together. 



4. CARDAMINE, 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. 

 (A Greek name, in Dioscorides, for some Cress, from the cordial or cardiacal 

 qualities.) — 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 from a tuberif- 

 erous base, simple ; root-leaves round and rather heart-shaped ; lower stem-leaves 

 ovate or rhombic-oblong, somewhat petioled, the upper almost lanceolate, all 

 somewhat angled or sparingly toothed ; pods linear-lanceolate, pointed with a 

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

 ows 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 and S. Pennsylvania to Wisconsin and northward. 



2. C. rotundifolia, Michx. (Mountain Water-Cress.) Stems branch- 

 ing, weak or decumbent, making long runners ; root fibrous ; leaves all much alike, 

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

 frecpiently 3-lobed or of 3 leaflets ; pods linear-awl-shaped, pointed with the 

 style; stigma minute; seeds oval-oblong. — Cool shaded springs, Pennsylvania 

 and southward along the mountains. May, June. — Leaves with just the taste 

 of the true Water-Cress. Flowers white, smaller than in No. 1. 



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

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

 nearly none. — Alpine summits of the White Mountains and'Katahdin, Maine 

 (J. W. Chickering). July. — Flowers 1-5, white. Pods 1' long, turgid, the 

 convex valves 1 -nerved. (Eu.) 



* * Root perennial : leaves pinnate : flowers showy. 



4. C. pratensis, L. (Cuckoo Flower.) Stem ascending from a short 



