368 Miscellanies. 



used by Muhlenberg, Nuttall, Elliott, and Bigelow, that some of our 

 most distinguished Botanists did question whether it was really distinct 

 from Persoon's Arabis rhoraboidea : and it was simply to determine 

 the fact, conclusively, that my specimens were presented to the 

 Academy. 



I have already mentioned that Prof. De Candolle had satisfied 

 himself, by an actual examination of Michaux's Herbarium : and I 

 may add that his descriptions of the two plants, in his Systema, can 

 scarcely be improved. Their distinct character has also been ex- 

 pressly recognised by my friend. Prof. Torrey, whose botanical acu- 

 men has rarely if ever been surpassed, in our country. Under these 

 circumstances, I confess, I was surprised, when I saw so eminent 

 and accomplised a Botanist as Professor Hooker, declaring, at this 

 late day, that the aforesaid plants had been " ascertained " to be 

 " the same /" It seems extraordinary, to me, that there should yet 

 be so much confusion, and such conflicting opinions on a point so 

 easily setded : and I can account for it only by supposing that those 

 gentlemen who confound the two species together, have never, in 

 fact, met with the genuine Cardamine rotundifolia, of Michaux. 



I will conclude these remarks by presenting, in contrast, the prom- 

 inent characteristics of the two plants, as I have observed them for 

 several years past. 



Arabis Rhomboidea, Persoon, Cardamine rhomboidea. DC. 



Root tuberous, with comparatively few fibres, — warmly acrid. 



Stem erect; mostly simple, except when wounded or broken oiF, 

 in which case a branch or two will succeed the injury. 



Leaves, the radical ones roundish, on long petioles, proceeding 

 from the tuber ; lower stem-leaves rhomboid ovate, on short petioles j 

 upper leaves sessile, lance oblong, and somewhat incisely toothed. 



Flowers, with large and conspicuous white corollas, fully equal 

 in size to those of Cardamine pratensis, of Europe. 



The plant, after maturing its fruit, speedily withers and disappears. 

 After the first week in June, it is difficult to find a vestige of it. 



Cardamine Rotundifolia, Mx. 



Root constantly j^Srows, fibres numerous, — sapor inconsiderable, 

 bitterish. 



Stem weak and soon becomes procumbent, sending out slender 

 branches from the axils of the leaves, especially after flowering : 

 which branches are clothed with small, orbicular leaves. 



