90 New Genera and Species of 



the leaves and flowers, the resemblance is striking. The style, 

 however, is very evident in the latter, but is almost wanting in 

 L. Michauxii. The difference in the direction of the radicle 

 seems also to be constant. From the appearance of the dried 

 specimens, I am of opinion that the flowers in the second 

 species are pale yellow. Michaux states that the peduncles are 

 solitary and one-flowered ; but I observed his specimens to be 

 caulescent, the short assurgent stems bearing elongated one- 

 flowered peduncles, as in the southern species. 



For my first knowledge of the L. aurea I am indebted to 

 my friend Dr. Short of Kentucky, who shared with me the 

 specimens he received from Dr. Leavenworth, its discoverer. 

 Subsequently I received some excellent specimens from Dr. 

 L. himself. Its general appearance is that of a Cardamine, 

 and I supposed it might be a species of that genus, but on ex- 

 amining the seed I was surprised to find the embryo almost 

 perfectly straight, so that the plant could not be referred to 

 either of De Candolle's great suborders of Cruciferas, the 

 cotyledons being accumhent in Pleurorhizje, and incumbent 

 in Notorhizje. Indeed it is the only species belonging to 

 this family, with which I am acquainted, in which the embryo 

 (except in the earliest state) is straight.* 



After I had completed my description of this plant, I re- 

 ceived from Dr. Short a good specimen of Cardamine unifiora, 

 a species which I had seen in Michaux's herbarium, and which 

 1 was very desirous of examining again, and comparing with 

 the Leavenworthia. It proved to be a second species of the 

 genus, readily distinguishable by the almost entire absence of 

 the style. 



Respecting the value of characters derived from the embryo 

 as the basis of classification in this large order, some of the 

 met distinguished modern botanists differ in opinion. Schkuhr 

 and Gaertnsr were well acquainted with the principal diversi- 

 ties of structure which the embryo in Crucifcra! exhibits. 



\ * in ihe Reclembriot among Leguminosa 



