CRUCIFKR.E. (mustard FAMILY.) G7 



rootstock, simple ; leaflets 7-1.3, those of tiic lower leaves rounded and stalked ; 

 of the upper ones oMoufj; or linear, entire, or slifilitly anj^lcd-toothed ; petals 

 (white or rose-color) thrice the leuf^th of the calyx. -^ Wet places and bogs, 

 Vermont to New Jersey, Wisconsin, and northward : rare. May. (Eu.) 

 * * * Root mosthj hiemufil or annmil : leaves pinnate: Jlotcrrs small, white. 



5. C. hirstlta, L. (Small Bitter Cress.) Beset with scattered hairs, 

 or glabrous ; stems (3'- 12' iiij;h) erect or a.--cen(ling from the sjjreadin;^- cluster 

 of root-leaves ; tiieir leaflets rounded, those of the upjier leaves oblong or linear 

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

 erect or ascending in line with the pedicel; style very short or almost none. 

 (C. rennsylvanica, Muhl. ; usually tallci- and more leafy-stemmed than the true 

 European C. hirsuta, the stamens always 6, and the pods less erect.) — Wet 

 places: common. May -July. (Eu.) 



Var. sylv^tica (C. sylvatica, Link., C. Virginica, Michx.) grows in drier 

 places, is more slender, and has pods more erect than their ascending or spread- 

 ing pedicels, the style evident. — Commoner southward. (Eu.) 



5. ABABIS, L. Rock Cress. 



Pod linear, flattened ; the valves plane or convex, more or less l-ncrved in 

 the middle, or longitudinally veiny. Seeds usually margined or winged. Coty- 

 ledons accumbent. — Leaves seldom divided. Piowers white or purple. (Name 

 from the country, Arabia. See Linn. Phil. Bot. § 235.) 



§ I . Seeds in one row in each cell, being nearly us broad as the partition. 

 * Low, chiijly biennials, diffuse or spreading from the base. 



1. A. Ludovici^na, Meyer. Nearly glabrous, often annual; leaves all 

 pinnatclj parted into ol)long or linear few-toothed or entire divisions, those of 

 the lower leaves numerous ; flowers small, white ; pods rather broadly linear 

 and spreading, flat ; seeds wing-margined. (Cardamine Ludo viciaua, //oo/j.) — 

 Open grounds, Virginia ? to Illinois and southward. 



2. A. lyrata, L. Hoot biennial ; plant mostly glabrous, except the Igrate- 

 pinmitijid root-leans, stem-leaves scattered, spatidate or linear with a tapering 

 base, sparingly toothed or entire ; petals white, much longer than the yellowish 

 calyx ; pods long and slender, flat, ascending or spreading ; the seeds margin- 

 less. — On rocks. New England to Kentucky along the mountains, Minnesota 

 and northward. April -July. — Radicle sometimes obliijue, or even dorsal. 



A. Tii.vLiXxA, L., resembles the last, but the root-leaves are hardly if at all 

 lyratc, the stem more strict, flowers smaller, and the cotyledons uniformly in- 

 cumbent ; so it is refeiTcd to Sisymbrium, p. 70. 



3. A. petraea, Lam. Root perennial, mnltiripitnl : leaves sparingly pinna- 

 tifid-toothed or incised, sometimes entire; petals rose-color or nearly white; pods 

 shorti-r and less flat than in A. lyrata : otherwise similar. — Rocks, L. Superior? 

 Wilioughby Mountain, Vermont, //. Mann. 



4. A. dent^ta, Torr. & Gray. Roughish-pubescent, slender (10-20 

 high) ; liaves oblong, very obtuse, unequally and sharply toothed; those of the 

 stem numerous, halj'rlasping and f(v<d at the ba.sc, of the root broader and 

 tapering into a short petiole; petals (whitish), scarcely exceeding the caly.x. 



