SisYMBRicM. CRUCIFER^. 9S 



late, attenuate at the base; siliques pubescent, terete, tondose, linear ; 5 times 

 the length of the pedicels. Hook. ! fi. lior.-Am. 1. p. 62. 



u. leaves mostly entire. Ledeb. — Hook. I. c. 



0. leaves sinuate-toothed and somewhat pinnatifid. Ledrb. — Hook. I. c. 



Rocky Mountains, lat. 52°-57°, to Arctic America ! — Stems 3-6 inches 

 high. Radical leaves numerous, rosulate, nearly an inch long: pubescence 

 stellate. Flowers 3-4 lines in diameter, " white or rose-color." Hooker. 



9. S. Thaliana (Gay) : annual; stems often many from one root, rather 

 naked, branching above, erect ; leaves (and lower part of the stem) hairy, 

 sparingly toothed ; radical ones ovate-oblong or spatulate-oblong, somewhat 

 petioled; siliques erect-spreading, twice as long as the pedicels. — Gay., in 

 ann. sci. nat. 7. p. 399; Hook. Ji. Bor.-Am. 1. p. 63; Meyer, pi. Cauc. 

 (1831) ;). 190. Arabis Thaliana, Linn.; Eng. hot. t. 901; Pursh! fl. 2. p. 

 437; DC. prodr. 1. p. 144. 



On rocks and in sandy fields, Massachusetts ! to Georgia ! west to Ken- 

 tucky. Introduced ? May. — Stem 3-10 inches high ; the upper part gla- 

 brous. Cauline leaves oblong or linear. Flowers very small. Siliques 

 straight, 6-8 lines long. Seeds in a single series. 



10. (S. glaucum (Nutt. ! mss.) : "annual, glaucous, much branched; 

 leaves entire ; radical ones small, spatulate ; cauline ovate, sagittate and 

 clasping, rather acute; siliques nearly straight, erect, compressed, with con- 

 vex: valves, four times the length of the pedicels. 



" Prairies of the Oregon, towards the Rocky Mountains. — About a foot 

 high, erect. Flowers very minute, pale purple. Petals cuneate-oblong, one- 

 half longer than the sepals. Siliques three-fourths of an inch long, glabrous: 

 style almost none. Seeds in a single, or partly in a double series. Cotyle- 

 dons decidedly incumbent." Nutt. 



11. S. virgatum (Nutt. ! mss.) : " biennial, canescently hirsute with sim- 

 ple and stellate hairs ; stem virgately branched from the base ; leaves lanceo- 

 late-linear, clasping, lower ones denticulate or entire ; siliques somewhat te- 

 rete, erect, 4-5 times the length of the pedicels ; seeds in a double series. 



" Hills of the Rocky Mountain range, near the sources of the Sweet Wa- 

 ter of the Platte. — About a span high. Leaves 6-8 lines long, and 2 Unes 

 wide. Flowers rather larger than in the preceding species, pale purple. 

 Petals obovate-spatulate, obtuse. Radicle almost exactly dorsal." Nutt. — 

 Septum very thin and translucent, marked with a distinct central nerve. 



12. S. paucijiorum (Nutt. ! mss.) : " biennial, hirsute with forked hairs 

 (not canescent) ; leaves entire, radical ones narrowly oblong-spatulate ; cau- 

 line lanceolate-linear, sessile; stem rather slender, branching from the base; 

 siliques long, pendulous ; seeds in a double series. 



" With the preceding. — Stem about a foot high, slender, nearly smooth 

 above. Flowers about twice as large as in the preceding species, white. 

 Petals exserted. Siliques three times as long as the pedicels." Nutt. 



X Doubtful species. 



13. S7 teres: small, erect, branched ; leaves all somewhat lyrately pin- 

 natifid; siliques rather short, linear, acuminate, on very short pedicels. — 

 Cardamine teres, Michx. ! ji. Bor.-Am. 2. p. 29 ; DC. syst. 2. p. 259. 



Vermont, on Lake Champlain, Michaux. ! — (1) Stem about 8 mches high, 

 a little roughened with short hairs. Leaves nearly glabrous, cauline ones with 

 3-4 pairs of lobes ; the lobes entire or toothed, terminal one 3-cleft. Ra- 

 cemes long : pedicels about a line long. Siliques erect, one-third of an inch 

 in length, pointed with a slender style one line in length ; valves very con- 

 vex. Seeds very numerous: cotyledons distinctly incumbent. — We have 



