436 CETJCIFEKAE (MUSTARD FAMILY) 



leaflets ; stem-leaves on sagittately appendaged petioles ; terminal leaflet mostly 

 3-lobed ; pods 2.5-3 cm. long, much exceeding the pedicels. — Springy places in 

 the mts., s. Va. and south w. 



* * * Fibrous-rooted alpine perennial with simple leaves ; northern. 



5. C. bellidifblia L. Dwarf (2-3.5 cm. high), densely tufted ; leaves ovate, 

 entire, or sometimes with a blunt lateral tooth, 2-10 mm. long, slender-petioled ; 

 flowers 1-6, white; pods 1.5-2 cm. long, upright, linear; style extremely short, 

 stout. — Arctic regions and alpine districts of the n. hemisphere. Represented 

 with us by 



Var. 14xa Lange. Looser and taller (4-11 cm. high) ; leaves 6-15 mm. long, 

 on very long petioles; pods 2-3 cm. long. — By alpine brooks, and in cold 

 ravines, Lab. to Mt. Katahdin, Me., and Mt. Washington, N. H. ; by a brook, 

 W. Baldwin, Me. {Miss Furbish). June, July. (Greenl.) 



* * * * Moot perennial ; leaves pinnate ; flowers showy. 



6. C. pratfinsis L. (Cdckoo Flower.) Stem ascending from a short root- 

 stock, simple ; leaflets numerous, those of the lower leaves rounded and stalked, 

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

 or rose-color) thrice the length of the calyx ;■ pod 2-3 cm. long, 2 mm. broad ; 

 style short. — Wet places and bogs. Lab. to Vt., N. J., Minn , and northw. ; 

 rare. May. Also introduced or a local escape in e. and s. N. E. (Eu.) 



*****Boot mostly biennial or annual; leaves pinnately 5-11-foliolate ; 

 flowers small, white. 



■1- Stamens 4; leaflets strigose-hispid upon the upper surface. 



i/l. C. hirsi^ta L. Leaves chiefly radical, with short and broad leaflets, but 

 those on the erect stem reduced and with narrow leaflets ; pods erect, on 

 ascending or appressed pedicels. — Moist places, s. Pa. to N. C, and "Mich." 

 (Eu.) Perhaps introduced. A doubtful specimen from w. Mass. {Miss VaiV). 



1- 1- Stamens normally 6; leaflets glabrous; stem leafy. 



8. C. parviflbra L. Very slender, subsimple, glabrous or slightly pubescent 

 upon the stem ; leaflets of the radical leaves oval or the terminal suborbicular ; 

 those of the cauline very narrow, linear, not confluent ; pods erect, on ascending 

 pedicels. {Q. hirsuta, var. sylvatica of some Am. auth.) — Rocky and barren 

 soil. Me. to Ga. and westw. (Eu.) A form more branched from the base and 

 with leaflets all narrow and often toothed has been described as C arenicola 

 Britton, growing in sandy soil in the Atlantic States but lacking constant 

 characters. 



y 9. C. pennsylvinica Muhl. Larger, nearly or quite glabrous ; leaflets 7-11, 

 the terminal one obovate, ihe lateral oblong, tending to be confluent along the 

 rhachis ; pods erect, on ascending pedicels. (C hirsuta Man. ed. 6, in great 

 part.) — Moist ground, common. Passes imperceptibly into a form (C. flexuosa 

 Britton, perhaps Withering) with fewer more flabelliform leaflets and spreading 

 pods. — Brooks, etc. 



31. ARABIS L. Rock Cress 



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

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

 less or winged. Cotyledons aocumbent or a little oblique. — Leaves seldom 

 divided. Flowers white or purple (rarely yellowish). (Name from the 

 country, Arabia.) 



§ 1. SISYMBRINA Wats. Seeds oblong or elliptical, very small, wingless, in 

 one row; cotyledons often more or less oblique; biennial or perennial, 

 branching from base. 



1. A. lyr&ta L. Mostly glabrous, except the lyrate-pinnatifld root-leaves ; 

 stem-leaves scattered, spatulate or linear with a tapering base, sparingly toothed 



