ORDER 13. CEUCIFER^E. 231 



minute, sessile. Common in streams and springy places throughout the country. 

 Aspects various ; st. varying from filiform to thick and fleshy. Lfts. few or many, 

 regular or not, lobed, toothed, angled or entire, always obtuse, terminal one gen- 

 erally 3-lobed. Pods always torulous and straight (except in (3) about 1' long. 

 Mar. Jn. 



13. VIHGINICA Hook. Slender and delicate ; Ifts. 1 or 2-toothed ; pods filiform, 

 incurved. Grows on rocks and sandy shores. 



2 C. pratensis L. CUCKOO FLOWER. St. ascending, simple ; Ivs. pinnately 7 15- 

 foliate, Ifts. petiolate, subentire, lower ones suborbicular, upper linear-lanceolate ; 

 sly. distinct. 14 Swamps, N. Y. to Arc., Am. "Whole plant smooth. St. round, 

 striate, 10 16 high. Lvs. few, 1^2' long, including the petiole. Lfts. small 

 or minute, regular. Fls. largo (6 8 ' broad), few. in a terminal raceme. Pet. 

 white or rose-color. Siliques nearly 1' in length, erect. Apr., May. 



3 C. rhomboidea DC. Sts. simple, erect or ascending, tuberiferous at base; 

 siliques linear-lanceolate. If Wet woods and meadows, common. Glabrous, 

 8 14' high. Tubers 1 to several, roundish, white, bearing one or several stems. 

 Radical leaves roundish, long-stalked, somewhat cordate, entire; stem Ivs. 

 oblong or rhomboidal, angular-subdentate, tha upper lanceolate, sessile. Ra- 

 cemes one or two, with white, showy, flowers. Styles 1" long ; stigmas capitate. 

 Apr. Jn. 



l3. PURPUREA. Torr. Slender, erect, few-leaved and purple-flowered. Cleve- 

 land, 0., tec. May. 



4 C. rotuiidifolia MX. Sts. decumbent, branching, finally stoloniferous ; Ivs. all 

 petiolate ,- siliques linear-subulate ; rt. fibrous. 1( Cool springs and rivulets in 

 Mts., Penn. to Car. (Buckley). Prostrate stems or runners 1 2f in length. Lvs. 

 roundish, subcordate angular, the lower 3-lobed or ternate, with the terminal 

 1ft. much the largest. Fls. smaller than in No. 3, white. May, Jn. 



5 C. bellidifolia L. Lvs. smooth, orbicular-ovate, nearly entire, petiolate; 

 cauline entire or 3-lobed; siliques erect. If A minute species, on the summits of 

 the White Mts. (Storrs), Ac. ; also, Arc., Am. to Cal. Stem 1$ 3' high. Lva 

 mostly radical, broadly oval or ovate, ^' long, on petioles as long as the stems. 

 Fascicles corymbous, each of 3 or 4 white flowers. Pet. oval, obtuse, about twice 

 as long as the calyx. Jl. 



6 C. spatulata MX. Lvs. hirsute, the radical spatulate, petiolate ; cauline 

 sessile, siliques spreading. (D Mts. of Car. and Ga. Sts. decumbent, slender, 

 6 8' long. Lvs. about 1' in length, the lower entire, obtuse ; the upper some- 

 what toothed, narrow. Rac. several, loose, with filiform, spreading, distant 

 pedicels. Fls. white. Pods straight, 1' long. Apr. 



7. ARABIS, L. ROCK CRESS. (Name from Arabia, the native coun- 

 try of some of the species.) Sepals mostly erect ; silique linear cotn- 

 pressed; valves each with one or three longitudinal veins, seeds in a 

 row in each cell, mostly margined, cotyledons accumbent or 

 . Fls. white. 



Leaves (all or at least the radical) pinnatifld Nos. 1, 2. 



* Leaves all undivided, toothed or entire, often clasping, (a) 



a Siliques short (612") and straight. Seeds not winged Nos. 8, 4. 



a Siliques longer (12'), straight or curved. Seeds not winged Nos. 5, 6. 



a Siliques long (3'), curved, pendant. Seeds winged Nos. T, 8. 



1 A. Ludoviciana Meyer. All the Ivs. pinnatifid or pinnate, smoothish; st 

 branched at base ; siltques and pedicels ascending ; sds. bordered. CD N. Car. 

 and Ky. (Curtis) to (Macon) Ga. Sts. 610' high, slender. Leaves 1 2'_long, 

 at first rosulate, of 69 pairs of oblong, few-toothed leaflets, rachis slightly 

 winged. Pods 710" by 1", valves veiny. Fls. minute, white. Mar., Apr. 



2 A. lyrata L. Upper Ivs. smooth, linear, entire; radical Ivs. lyrately pinnatifid, 

 often pilous: st. branched at base; pedicels spreading; siliques erect, feeds not 

 bordered,-^) On rocky hills, Can. and Wis. to Va. Sts. declined at base, 612 

 high. Root-lvs. numerous, rosulate, 13' long, i as wide, petiolate, pinnatifid or 

 sinuate-dentate, upper ones sublinear and subentire. Fls. middle size (3 long) 



