9± -V- w Genera and Species of c£c. 



broad silique, margined, and even winged seeds) is consider- 

 able, but it differs widely in the shape and color of the petals. 

 the structure of the dissepiment, and in many other respects. In 

 the broad Bilique and dissepiment (compared with any of the 

 Arabidese) it seems allied to some Alyssinese, especially if we 

 retain in that tribe the remarkable Selenia of Nuttall, which 

 resembles our plant in the transverse areolae of the dissepi- 

 ment, pinnatirid leaves, and yellow flowers. In that genus, 

 however, the fruit is broader, the style longer, and the seeds 

 are truly accumbent, although the radicle is unusually short, 

 and is directed horizontally with respect to the axis of the 

 fruit. Upon the whole I consider it more nearly related to 

 Selenia than to any other knQwn genus. 



Description of the Plate of Leavenworthla. 



:. 1. A young plant of L. aurea, of the natural size. 



2. A full grown plant of the same. 



3. A flower magnified. 



4. A petal do. 



5. The silique laid open to show the arrangement of 



the seeds. 



6. The replum and dissepiment, exhibiting the longi- 



tudinal nerve, and the funiculi. 



7. The embryo. 



8. A transverse section of the same. 



9. Pistil of L. Michauxii. 



10. Silique of the same. 



11. Embryo. 



