94 CRUCIFER^. Erysimum. 



removed this little-known plant to Sisymbrium, on account of the incum- 

 bent cotyledons ; but we are by no means certain that it belongs to this ge- 

 nus. DeCandoUe asks whether it may not be a Nasturtium. The speci- 

 mens in Michaux's herbarium are only in fruit. 



S. Icptopdalum (Raf.) Jl. Laulov. p. 2G8.— See note on p. 8G. 



14. TROPIDOCARPUM. Hook. ic. 1. t. 43. 



Silique linear or lanceolate-linear, compressed contrary to the septum ; 

 valves somewhat carinate. Septum very narrow, often incomplete. Seeds 

 oblong, compressed, not margined. Cotyledons narrow, shorter than the 

 radicle. Sepals equal at the base. — Herbaceous annuals. Leaves pinnatiiid. 

 Flowers small, yellow, in leafy racemes. 



1. T. gracile (Hook.) : nearly glabrous ; leaves pinnatifid; silique linear, 

 — Hook. I. c. 



Wet places on the plains around Monterey, Upper California, Douglas, 

 ■jSfuttall .'—Stem decumbent, 6-12 inches long, very sparingly hirsute. Radi- 

 cal leaves bipinnatifid, the others pinnatifid ; segments narrowly linear and 

 very acute. Flowers from the axis of the uppermost leaves, on slender pe- 

 duncles, 3-8 lines long. Sepals oblong. Petals obovate, erect, nearly twice 

 the length of the sepals. Silique about an inch long, attenuated into a short 

 style ; the septum sometimes nearly obliterated. 



2. T. scabriusculum (Hook.) : somewhat roughly hirsute ; leaves bipinna- 

 tifid ; silique lanceolate. — Hook. ! I. c. t. 52. 



With the preceding, Douglas! Nuttall.'— Differs from T. gracde chiefly m 

 its hu-sute pubescence, rather shorter leaves and peduncles, and somewhat 

 smaller flowers.— The ripe siliques of this species have the septum complete 

 the whole length. It is very narrow, so that, at the upper part, the opposite 

 placentEe are almost in contact. Hooker has not described the seeds of this 

 genus, probably because his specimens were immature. The cotyledons are 

 decidedly incumbent, but lie with their edges parallel to the septum ! 



15. ERYSIMUM. Linn.; DC. syst. 2. p. 491. 



Silique 4-sided. Calyx closed. Cotyledons oblong. 



§ Style short or scarcely any : calyx deciduous: leaves neither cordate 

 nor clasping : fiowers distinctly pedicellate.— ETysimastmm, DC. 



1. E. cheiranthoides (Linn.) : somewhat scabrous with a minute appres- 

 sed' pubescence ; leaves lanceolate, denticulate or entire ; siliques erect, 

 spreading-, twice the length of the pedicels; stigma smaW.—Pursh, f. 2. p. 

 436 ; DC. prodr. 1. p. 198; Hook.! f. Bor.-Am. 1. p. 64. E. parviflorum, 

 Pers.syn.2.p.l'd9;Nutt.!gen.2.'p.\^. . ,^ ,. 



Along streams, throughout the United States ! and Canada ! west to Mis- 

 souri and N. W. Coast. July-Aug.— or (2) Stem 1-2 feet high, simple 

 or branched. Pubescence 3-4-parted. Flowers small, yellow. Siliques 

 about an inch long, pointed with a short style.— A native also of Europe. 



2. E. lanceolat%im{R.Brown): canescently scabrous with an appressed 

 2-parted pubescence ; stem nearly simple ; leaves linear-lanceolate, the lower 

 ones usually toothed; claws of the petals longer than the calyx; siliques 



