BOTANICAL EXCURSION TO NORTH CAROLINA. 37 



fluous. Near the cave we saw some trees of Tillia hetero- 

 phylla, Vent. (T. alba, Michx. f.), and collected a few speci- 

 mens with unopened flower-buds. It appears to be the most 

 abundant species along the mountains. 



Our ride next day offered nothing of interest. Near 

 Staunton, we saw some patches of Delphinium consolida, 

 where it was pretty thoroughly naturalized in the time of 

 Pursh. We did not observe Spircea lobata, which Michaux 

 first met with in this vicinity, and which Pursh, as well as 

 later botanists, found in various parts of the valley. Passing 

 the town of Lexington in the evening, we arrived at the 

 Natural Bridge towards morning, where we remained until 

 Monday, and had an opportunity of botanizing for a short 

 time before we left. On the rocks we found plenty of As- 

 plenium Ruta-muraria, Sedun ternatum, and Draha ramo- 

 sissima with ripe fruit. In the bottom of the ravine, directly 

 under the stupendous natural arch (the point which affords 

 the most impressive view of this vast chasm), we collected 

 specimens of Heuchera villosa, Michx., in fine flower on the 

 28th of June ; although, in the higher mountains of North 

 Carolina, where it also abounds, the flowers did not appear 

 until near the end of July. This species is excellently de- 

 scribed by Michaux, to whose account it is only necessary to 

 add that the petals are very narrow, appearing like sterile fila- 

 ments. Although a smaller plant than H. Americana, the 

 leaves are larger, and vary considerably in the depths of the 

 lobes. It is both the H. villosa and H. caulescens of Pursh, 

 who probably derived the latter name from the strong elon- 

 gated rhizoma, often projecting and appearing like a suf- 

 frutescent stem, by which the plant is attached to the rocks ; 

 since he does not describe the scape as leafy, nor is this at 

 all the case in the original specimens. The H. caulescens of 

 Torrey and Gray's Flora with the synonym, must also be 

 united with H. villosa, which in that work is chiefly described 

 from specimens collected by Dr. Short in Kentucky, where 

 everything seems to grow with extraordinary luxuriance. 

 With these, the plant we collected entirely accords except 

 that the leaves are mostly smaller, and more deeply lobed ; 



