32 CRUCIFERJS. (MUSTARD FAMILY.) 



2. D. ffll^\illi:i, Nutt. Rootstock interrupted, forming a string of toothed 

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

 toothed and incised, often 2-3-cleft. (D. laciniata, var. 3., Torr. $ Gr.) W. 

 >Yw York, and Penn., Nuttatt! 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 

 intermediate between No. 1 and No. 3. 



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

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

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

 lateral ones deeply 2-lobed. Rich 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. D. lieteropliylla, Nutt. Rootstock. necklace-form, obscurely toothed ; 

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

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

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

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



5. 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. 

 (From KdpSauov, 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. rliomboidea, DC. (SPRING CRESS.) Stems upright, tuberifer- 

 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. pnrpurca, 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. rotimdifolia, Michx. (AMERICAN WATER-CRESS.) Stemi 

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

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

 lowest frequently 3-lobcd 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 summer 

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



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

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



