Oedbb 13.— CEUCIFBE^. 231 



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

 Aspects various ; st varying from flUform 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 ;8) about 1' long. 

 Mar. — Jn. 

 • 13. TiRGiNicA Hook. Slender and delicate ; lfts. 1 or 2-toothed ; pods filiform 

 incurved. — Grows on rocks and sandy shores. 



2 C. prat^nsis L. Cdckoo Flower. St. ascending, simple ; Ivs. pinnaidy 1 — 15- 

 foliate, lfts. petiolaie, subentire, lower ones suboriicular, upper linear-lanceolate; 

 sty. distinct. — If Swamps, N. T. to Arc, Am. "Whole plant smooth. St. round, 

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

 or minute, regular. Fls. large (6 — 8" broad), few, in a terminal raceme. Pet. 

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



3 C. rliomboidea DO. Sis. simple, erect or ascending, Ivheriferous at hose; 

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

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

 Badical leaves roundish, long-stalked, somewhat cordate, entire; stem lvs. 

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

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

 Apr. — Jn. 



/?. PUKPUREA Torr. Slender, erect, few-leaved and purple-flowered. — Cleve- 

 land, 0., &c. May. 



4 C. rotundifdlia Mx. Sts. decwnlent, iranching, finally stoloniferous ; lvs. all 

 petiolate; siliques linear-subulate; rt. fibrous. — !(. 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. Pis. 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. — H A minute species, on the summits of- 

 the White Mts. (Storrs), &c. ; also, Arc, Am. to Cal. Stem 1^ — 3' high. Lvs. 

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

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

 as long as the calyx. Jl. 



6 C. apatulata Mx. 'l/os. hirsute, the radical spatulate, petiolate ; cauline 

 sessile, siliques spreading. — 2) 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. Rao. several, loose, with filiform, spreading, distant 

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



7. ARABIS, L.- Rock Cress. (Name from .4ra6ia, the native coun- 

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

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

 single row in each cell, mostly margined, cotyledons accumbent or 

 oblique. — Fls. white. 



* Leaves (all or at least the radical) pinnatifltl Nos. 1, 3. 



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



a Siliques short (6 — 12'0 and straight. Seeds not winged Nos. 8, 4. 



a Siliques longer (1—2'). straight or curved. Seeds not winged Nos. 6, 6. 



a Siliques long (8'), curved, pendant. Seeds winged Nos. 7, 8. 



1 A. Ludovici^na Meyer. All the lvs. pinnatifid or pimiate, smoothish; st. 

 branched at base ; sUiques and pedicels ascending ; sds. iordered.—^ N. Car. 

 and Ky. (Curtis) to (Macon) Ga. . Sts. 6—10' high, slender. Leaves 1—2' long, 

 at first rosulate, of 6—9 pairs of oblong, few-toothed leaflets, rachis slightly 

 winged. Pods Y— 10" by 1", valves veiny. Fls. minute, white. Mar., Apr. . 



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

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

 bordered.—® On rocky hills. Can. and Wis. to Ta. Sts. declined at base, 6—12 

 high. Root-lvs. numerous, rosulate, 1-^3' long, i as wide, petiolate, pinnatifid or 

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



