(MUSTARD FAMILY.) 63 



- -i- Pod linear (or oblong or even globular in n. 11). 

 ~* Cotyledons accumbent. 



11. Nasturtium. Pod often short; valves strongly convex, nerveless. Seeds small, in 



2 rows in each cell. Flowers yellow or white. 



12. Barbarea. Pod somewhat 4-sided ; valves strongly 1-nerved. Seeds in 1 row. Flowers 



yellow. 



H- -H- Cotyledons incumbent or partially so. 



13. Hesperis. Pod terete, elongated ; stigma-lobes narrow, erect. Flowers large, purple. 



14. Erysimum. Pod 4-sided; valves strongly 1-nerved ; stigma broadly 2-lobed. Pu 



bescence of appressed 2-3-parted hairs. Flowers yellow. 



15 Sisymbrium. Pod angled orteretish; valves 1-3-nerved; stigma small. Flowers 

 yellow or white, small. 



16. Thelypodium. Pod teretish ; valves 1-nerved ; stigma entire. Cotyledons ob- 



liquely incumbent. Flowers rose-color. Leaves auricled. 

 H. Cotyledons conduplicate. 



17. Brassica. Pod beaked or pointed beyond the end of the valves, or tipped with a 



rigid style, nearly terete, or 4-sided. Flowers yellow or whitish. 



* * Pod short ; the boat-shaped valves conduplicate or much flattened contrary to the 

 narrow partition. Flowers white. 



18. Capsella. Pod many-seeded, obcordate-triangular, wingless. Cotyledons incumbent. 



19. Thlaspi. Pod several-seeded, obovate or obcordate, winged. Cotyledons accumbent. 



20. Lepiclium. Pod 2-seeded, flat, scale-shaped. Cotyledons incumbent or accumbent. 



21. Senebiera. Pod 2-seeded, didymous ; the valves rugose, separating at maturity from 



the little partition as 2 closed 1-seeded nutlets. Cotyledons incumbent, narrow. . 



SERIES II. Pods indehiscent, continuous or transversely jointed; joints 



1-celled. 



22. Cakile. Pod short, 2-jointed ; joints 1-seeded. Cotyledons plane, accumbent. 



23 > Itaplianus. Pod elongated, several-seeded, continuous, or constricted between the 

 seeds and moniliform. Cotyledons conduplicate. 



1. SELENIA, Nutt. 



Pod large, oblong-elliptical, flat ; the valves nerveless. Seeds in 2 rows in 

 each cell, rounded, broadly winged ; cotyledons accumbent ; radicle short. 

 A low annual, with once or twice pinuatifid leaves and leafy-bracteate racemes 

 of yellow flowers. (Name from o-eA^j/Tj, the moon, with allusion to Lunaria, 

 which it somewhat resembles in its pods.) 



1. S. aiirea, Nutt. Lobes of the simply pinnatifid leaves entire or toothed ; 

 pod %' long, on elongated spreading pedicels, beaked by the long slender style. 

 Mo. and Kan. to Tex. 



2. LEAVENWORTHIA, Torr. 



Pod broadly linear or oblong, flat ; the valves nerveless, but minutely re- 

 ticulate-veined. Seeds in a single row in each cell, flat, surrounded by a thick 

 wing. Embryo straight ! or the short radicle only slightly bent in the direc- 

 tion which if continued would make the orbicular cotyledons accumbent. 

 Little winter annuals, glabrous and often stemless, with lyrate leaves and short 

 1 -few-flowered scape-like peduncles. (Named in honor of the late M. C. 

 Leavenworth.) 



1. L. MichatlXii, Torr. Scapes 2-6' high; leaf-lobes usually numer- 

 ous (7-15); Detals purplish or nearly white with a yellowish base, obtuse; 



