CRl'OIFEH.*:. (mI'STAUI) kamflv.) 65 



* Root perennial ; leaves simple. 

 1. C. rhomboidea, ])C. (Simung Ckkss.) .stems upright from a tu- 

 berous base and slox/ir rootsiock bearing small tubers, sivijile ; root-leaves round 

 aud often heart-shaped ; lower stem-leaves ovate or rlioinl)ic-ol)long, somewhat 

 petioled, tlie upper almost lanceolate, sessile, all often sparin<;ly toothed ; pods 

 linear-lanceolate, pointed with a slender style ti])ped with a consjjicuous stigma ; 

 seeds round-oral. — Wet meadows aud springs; common. April -June. — 

 Flowers large, wliite. 



Var, purptirea, Torr. Lower (4-6' high), and usually slightly pnbes- 

 lont; flowers rose-pur])le, appearing earlier. — Along streams in rich soil. 

 Western N. Y. to Md. and Wise. 



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

 ing, weak or decumbent, making long runners, root Jibrous : leaves all much 

 alike, roundish, somewhat angled, often heart-shaped at the ba.se, petioled ; 

 pods small, linear-awl-shaped, pointed with the slender style ; stigma minute ; 

 seeds oval-oblong. — Cool shaded springs, N.J. (Middletown, M'/7//.s) to Ky., 

 and southward along the mountains. May, June. — P'lowers white, smaller 

 than in u. 1. 



3. C. bellidifblia, L. Z)zror/'(2-3' high), alpine, tufted; leaves ovate, 

 entire, or sometimes with a blunt lateral tooth (4" long), on long petioles; 

 pods 1' long, upright, linear ; style nearlij none, stout. — Summits of the White 

 Mountains and Katahdiu, Maine. July. — Flowers 1 -5, white. (Eu.) 



* * Root perennial ; leaves pinnate ; Jlowers show g. 



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

 rootstock, simple ; leaflets 7 - 13, those of the lower leaves rounded and stalked, 

 of the upper oblong or linear, entire, or slightly angled-toothed ; petals (white 

 or rose-color) thrice tl;e length of the calyx ; pod 9-15" long, \" broad j stvle 

 short. — Wet places and bogs, Vt. to N. J., Wise, and northward; rare. 

 May. (Eu.) 



* * * Root mosthj biennial or annual; leaves pinnate ; flowers small, white. 



5. C. hirsuta, L. (Small Bitter Cress.) Glabrous or beset with 

 scattered hairs, stems (3' -2° high) erect or ascending from the spreading 

 cluster of root-leaves; their leaflets rounded, those of the upper leaves oblong 

 or linear and often confluent, all either toothed, angled, or entire ; pods linear, 

 very narrow, erect or ascending; style variable. — Wet places; common. 

 May -July. The ordinary form corresponds closely to the European var. 

 sylvAtica, Gaud. The typical imperfectly developed annual form, with only 

 4 stamens and rather strict pods, occurs very rarely. A form answering to C. 

 parviflora of Europe, with mostly linear leaflets and pods often erect on sjiread- 

 ing pedicels, is occasionally found in drier localities. (Eu., Asia.) 



6. ARABIS, L. KocK Cre.ss. 



Pod linear, flattened ; placentas not thickened ; the valves plane or convex, 

 more or less 1-nerved in the middle, or longitudinally veiny. Seeds usually 

 margined or winged. Cotyledons accumbent or a little oi)li(pie. — Leaves sel- 

 dom divided. Flowers white ur i)urple. (Name from the country, Arabia. 

 See Linn. Phil. Bot. § 235.) 



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