30 CKUCIFER^E. (MUSTARD FAMILY.) 



2. L. globosa, Watson. Biennial, hoary-tomentose ; stems clustered, 

 mostly simple, 1 high ; leaves lanceolate, tapering to the hase, mostly entire; 

 style longer than the globular 1 -4-seeded silicle; seeds wingless. Bluffs of 

 the Cumberland Eiver, Tennessee. April. 



15. ALYSSUM, Tunrn. 



Silide flat, 2 -4-seeded. Filaments often toothed. Flowers (of ours) white. 



Otherwise like the last. 



1. A. maritimum, L. (SWEET ALYSSUM.) Perennial, prostrate; 

 leaves lanceolate ; silicle 2-seeded. North Carolina. Introduced. 



16. CAMELINA, Crantz. 



Silicle ovoid or pear-shaped, flattened parallel to the broad partition ; valves 

 1-nerved. Seeds numerous, oblong. Cotyledons incumbent. Stvle slender. 



Flowers small, yellow. 



1. C. sativa, Crantz. Leaves alternate, sagittate ; silicle large. Fields, 

 North Carolina, and northward. Introduced. (T). 



17. SENEBIERA, Poir. 



Silicle didymous, compressed contrary to the narrow partition ; the cells 

 globular, 1-seeded, crested or pitted, indeliiscent, at maturity separating from 

 the partition. Cotyledons incumbent. Annual or biennial diffuse strong- 

 scented herbs, with pinnattdy lulied or divided leaves, and minute white flow- 

 ers, in short racemes, opposite the leaves. Stamens 2, 4, or 6. 



1. S. pinnatiflda, DC. Stem prostrate ; leaves deeply pinnatifid, with 



the numerous lobes toothed on the upper edge ; silicle pitted, emarginate at 

 both ends. Waste places, Florida to North Carolina. March -Ma}'. Ka- 

 cemes many-flowered. 



2. S. Coronopus, Poir. Stem prostrate ; leaves deeply pinnatifid, with 

 the lobes entire, toothed, or pinnatifid; silicles not emarginate, the margins 

 crested. Waste places. Introduced. March - April. 



18. LEPIDIUM, L. PKPPERGRASS. 



Silicle rounded or obcordate, compressed contrary to the narrow partition ; 

 valves carinate; cells 1 seeded. Cotyledons accumbent and incumbent. 

 Petals sometimes wanting. Stamens 2, 4, or 6. Leaves entire, toothed, 

 or pinnatelv divided. Flowers minute, in terminal racemes. 



1. L. Virginicum, L. Smooth; stem erect, much branched; leaves 

 lanceolate, sharply toothed, the lowest tapering and mostly pinnatifid toward 

 the base ; silicle orbicular, wingless ; cotyledons accumbent ; stamens mostly 

 two. Waste places, very common. March - June. (I) Stem 1- 2 high. 



19. CAPSELLA, Vent. SHEPHERD'S PURSE. 



Silicle triangular wedge-shaped, flattened contrary to the narrow partition, 

 many-seeded; valves wingless. Cotyledons incumbent. An annual herb, 



