454 FLORA. 



Mature pods erect, 0.5-1 mm. wide. 



Flowers 4-5 mm. wide; plants of swamps, streams, or wet grounds. 

 Segments of basal leaves 4-25 mm. wide; plant 2-9 dm. tall. 



3. 6". Pennsylvanica. 

 Segments of basal leaves 1-3 mm. wide; plant 1-3 dm. tall. 



4. C. arenicola. 

 Flowers 2-3 mm. wide; plant of dry rocky situations. 



5. C. parvijiora. 

 Mature pods divergent or ascendirrg, more than i mm. wide. 



6. C.flexuosa. 

 Leaf-segments few, large, the terminal one 2-5 cm. wide, deeply cordate. 



7. C. Clematitis. 



** Leaves entire, toothed, or rarely with i or 2 lateral segments. 

 Dwarf, alpine ; leaves nearly entire, long-petioled. 8. C. bellidifoha. 



Erect or decumbent ; leaves more or less toothed or lobed. 



Flowers purple ; stem erect. 9. C. purpurea. 



Flowers white. 



Stem erect from a tuberous base. 10. C. bulbosa. 



Stem decumbent, stoloniferous; roots fibrous. u. C. rot undif alia. 



1. Cardamine pratensis L. MEADOW BITTER-CRESS. CUCKOO-FLOWER. 

 (I. F. f. 1724.) Glabrous, 2-5 dm. high; roots fibrous. Leaves pinnately divided, 

 lanceolate or oblong in outline, the lower petioled, the upper sessile; divisions 3-7 

 pairs and an odd one; petals three times the length of the calyx; pedicels slender, 

 8-12 mm. long in fruit; pods 1.5-3 cm. long, 2 mm. wide; style 1-2 mm. long, 

 thick. In wet meadows and swamps, Lab. to N. J., Br. Col. and Minn. Also in 

 Europe and northern Asia. April-May. 



2. Cardamine hirsuta L. HAIRY BITTER-CRESS. (I. F. f. 1725.) More or 

 less pubescent; stem usually little branched, 1-2.5 dm. tail. Leaves nearly all 

 basal, 2-IO cm. long, pinnate, the terminal segment orbicular or broader than long, 

 entire or few-toothed, the lateral ones 2-5 pairs; stem leaves few, their segments 

 linear, or linear-oblong; flowers 4 mm. broad, white; pods linear, about 2.5 cm. 

 long and i mm. wide, erect on ascending pedicels 4-8 mm. long when mature; 

 style almost none. In moist places, Penn. to Mich., Neb. and N. Car. Also in 

 Europe and Asia. March-May. 



3. Cardamine Pennsylvanica Muhl. PENNSYLVANIA BITTER-CRESS. (I. F. 

 f. 1726.) Glabrous or rarely with a few hairs; stem erect, 2-9 dm. tall, usually 

 much branched, leafy. Basal leaves 0.5-1.5 dm. long, the terminal segment obo- 

 vate, oval or suborbicular, the lateral 4-8 pairs oblong, oval, or obovate; flowers 

 about 4 mm. broad, white; pods narrowly linear, 1.5-3 cm. long, less than I mm. 

 wide, erect when mature on ascending or divergent pedicels 4-6 mm. long; style 

 about i mm. long. In swamps and wet places, Newf. to Minn., Mont., Fla., Tenn. 

 and Kans. April-June. 



4. Cardamine arenicola Britton. SAND BITTER-CRESS. (I. F. f. 1727.) 

 Glabrous, usually branched from the base, leafy, erect, 1.5-3 dm. high. Segments 

 of the leaves numerous, linear or linear oblong, 1-3 mm. wide, obtusish, entire, or 

 with 1-3 small teeth; flowers about 4 mm. broad, white; mature pods erect, alx>ut 

 2 cm. long. 0.5-1 mm. wide, their pedicels ascending; style almost wanting. In 

 moist or wet sandy soil, Conn, to Fla., Ky. and Tenn. March-April. 



t. Cardamine parviflora L. SMALL-FLOWERED BITTER CRESS. (I. F. f. 

 .) Glabrous or sparingly pubescent ; stem weak, erect or ascending, very 

 slender or almost filiform, 0.5-4 dm. long, usually leafy up to the racemes, the 

 leaves scattered. Segments of the leaves numerous, oblong or linear, or the ter- 

 minal one sometimes orbicular, 1-4 mm. wide; mature pods 2-5 cm. long or less, 

 rather less than i mm. wide, erect on ascending pedicels, 4-10 mm. long, the axis 

 of the racemes commonly zigzag ; flowers scarcely more than I mm. broad, white; 

 style almost wanting. On rocks, Quebec to W. Ont., Ore., south to Mass, and Ga. 

 Also in northern Europe and Asia. April-May. 



6. Cardamine flexuosa With. WOOD BITTER-CRESS. (I. F. f. 1729.) Gla- 

 brous; stem leafy, 1.5-4 dm. tall. Leaf segments obovate, oval, oblong or linear, 

 the terminal one sometimes orbicular, narrowed rounded or subcordate at the base, 

 1-2 cm. wide, the lateral ones usually much narrower; flowers white, 4 mm. broad; 

 pods ascending or divergent, on spreading or ascending pedicels, 1.5-3 cm - l n ? 

 I mm. wide or rather more; style minute or none. In wet woods, streams and 



